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a|x+2|-(1-a)|x-2|+3=0 equation

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Numerical solution:

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The solution

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a*|x + 2| - (1 - a)*|x - 2| + 3 = 0
$$\left(a \left|{x + 2}\right| - \left(1 - a\right) \left|{x - 2}\right|\right) + 3 = 0$$
Detail solution
For every modulo expressions in the equation
allow cases, when this expressions ">=0" or "<0",
solve the resulting equation.

1.
$$x + 2 \geq 0$$
$$x - 2 \geq 0$$
or
$$2 \leq x \wedge x < \infty$$
we get the equation
$$a \left(x + 2\right) - \left(1 - a\right) \left(x - 2\right) + 3 = 0$$
after simplifying we get
$$a \left(x + 2\right) - \left(1 - a\right) \left(x - 2\right) + 3 = 0$$
the solution in this interval:
$$x_{1} = - \frac{5}{2 a - 1}$$

2.
$$x + 2 \geq 0$$
$$x - 2 < 0$$
or
$$-2 \leq x \wedge x < 2$$
we get the equation
$$a \left(x + 2\right) - \left(1 - a\right) \left(2 - x\right) + 3 = 0$$
after simplifying we get
$$a \left(x + 2\right) - \left(1 - a\right) \left(2 - x\right) + 3 = 0$$
the solution in this interval:
$$x_{2} = - 4 a - 1$$

3.
$$x + 2 < 0$$
$$x - 2 \geq 0$$
The inequality system has no solutions, see the next condition

4.
$$x + 2 < 0$$
$$x - 2 < 0$$
or
$$-\infty < x \wedge x < -2$$
we get the equation
$$a \left(- x - 2\right) - \left(1 - a\right) \left(2 - x\right) + 3 = 0$$
after simplifying we get
$$a \left(- x - 2\right) - \left(1 - a\right) \left(2 - x\right) + 3 = 0$$
the solution in this interval:
$$x_{3} = \frac{1}{2 a - 1}$$


The final answer:
$$x_{1} = - \frac{5}{2 a - 1}$$
$$x_{2} = - 4 a - 1$$
$$x_{3} = \frac{1}{2 a - 1}$$
The graph
Sum and product of roots [src]
sum
                                                                                                //  -5             5          \     //  -5             5          \       //   1                               \     //   1                               \
    //-1 - 4*a  for And(a <= 1/4, a > -3/4)\     //-1 - 4*a  for And(a <= 1/4, a > -3/4)\       ||--------  for -------- <= -2|     ||--------  for -------- <= -2|       ||--------  for And(a > 1/4, a < 1/2)|     ||--------  for And(a > 1/4, a < 1/2)|
I*im|<                                     | + re|<                                     | + I*im|<-1 + 2*a      -1 + 2*a      | + re|<-1 + 2*a      -1 + 2*a      | + I*im|<-1 + 2*a                           | + re|<-1 + 2*a                           |
    \\  nan              otherwise         /     \\  nan              otherwise         /       ||                            |     ||                            |       ||                                   |     ||                                   |
                                                                                                \\  nan         otherwise     /     \\  nan         otherwise     /       \\  nan             otherwise        /     \\  nan             otherwise        /
$$\left(\left(\operatorname{re}{\left(\begin{cases} - 4 a - 1 & \text{for}\: a \leq \frac{1}{4} \wedge a > - \frac{3}{4} \\\text{NaN} & \text{otherwise} \end{cases}\right)} + i \operatorname{im}{\left(\begin{cases} - 4 a - 1 & \text{for}\: a \leq \frac{1}{4} \wedge a > - \frac{3}{4} \\\text{NaN} & \text{otherwise} \end{cases}\right)}\right) + \left(\operatorname{re}{\left(\begin{cases} - \frac{5}{2 a - 1} & \text{for}\: \frac{5}{2 a - 1} \leq -2 \\\text{NaN} & \text{otherwise} \end{cases}\right)} + i \operatorname{im}{\left(\begin{cases} - \frac{5}{2 a - 1} & \text{for}\: \frac{5}{2 a - 1} \leq -2 \\\text{NaN} & \text{otherwise} \end{cases}\right)}\right)\right) + \left(\operatorname{re}{\left(\begin{cases} \frac{1}{2 a - 1} & \text{for}\: a > \frac{1}{4} \wedge a < \frac{1}{2} \\\text{NaN} & \text{otherwise} \end{cases}\right)} + i \operatorname{im}{\left(\begin{cases} \frac{1}{2 a - 1} & \text{for}\: a > \frac{1}{4} \wedge a < \frac{1}{2} \\\text{NaN} & \text{otherwise} \end{cases}\right)}\right)$$
=
    //   1                               \       //  -5             5          \                                                    //   1                               \     //  -5             5          \                                             
    ||--------  for And(a > 1/4, a < 1/2)|       ||--------  for -------- <= -2|       //-1 - 4*a  for And(a <= 1/4, a > -3/4)\     ||--------  for And(a > 1/4, a < 1/2)|     ||--------  for -------- <= -2|     //-1 - 4*a  for And(a <= 1/4, a > -3/4)\
I*im|<-1 + 2*a                           | + I*im|<-1 + 2*a      -1 + 2*a      | + I*im|<                                     | + re|<-1 + 2*a                           | + re|<-1 + 2*a      -1 + 2*a      | + re|<                                     |
    ||                                   |       ||                            |       \\  nan              otherwise         /     ||                                   |     ||                            |     \\  nan              otherwise         /
    \\  nan             otherwise        /       \\  nan         otherwise     /                                                    \\  nan             otherwise        /     \\  nan         otherwise     /                                             
$$\operatorname{re}{\left(\begin{cases} - 4 a - 1 & \text{for}\: a \leq \frac{1}{4} \wedge a > - \frac{3}{4} \\\text{NaN} & \text{otherwise} \end{cases}\right)} + \operatorname{re}{\left(\begin{cases} - \frac{5}{2 a - 1} & \text{for}\: \frac{5}{2 a - 1} \leq -2 \\\text{NaN} & \text{otherwise} \end{cases}\right)} + \operatorname{re}{\left(\begin{cases} \frac{1}{2 a - 1} & \text{for}\: a > \frac{1}{4} \wedge a < \frac{1}{2} \\\text{NaN} & \text{otherwise} \end{cases}\right)} + i \operatorname{im}{\left(\begin{cases} - 4 a - 1 & \text{for}\: a \leq \frac{1}{4} \wedge a > - \frac{3}{4} \\\text{NaN} & \text{otherwise} \end{cases}\right)} + i \operatorname{im}{\left(\begin{cases} - \frac{5}{2 a - 1} & \text{for}\: \frac{5}{2 a - 1} \leq -2 \\\text{NaN} & \text{otherwise} \end{cases}\right)} + i \operatorname{im}{\left(\begin{cases} \frac{1}{2 a - 1} & \text{for}\: a > \frac{1}{4} \wedge a < \frac{1}{2} \\\text{NaN} & \text{otherwise} \end{cases}\right)}$$
product
                                                                                            /    //  -5             5          \     //  -5             5          \\ /    //   1                               \     //   1                               \\
/    //-1 - 4*a  for And(a <= 1/4, a > -3/4)\     //-1 - 4*a  for And(a <= 1/4, a > -3/4)\\ |    ||--------  for -------- <= -2|     ||--------  for -------- <= -2|| |    ||--------  for And(a > 1/4, a < 1/2)|     ||--------  for And(a > 1/4, a < 1/2)||
|I*im|<                                     | + re|<                                     ||*|I*im|<-1 + 2*a      -1 + 2*a      | + re|<-1 + 2*a      -1 + 2*a      ||*|I*im|<-1 + 2*a                           | + re|<-1 + 2*a                           ||
\    \\  nan              otherwise         /     \\  nan              otherwise         // |    ||                            |     ||                            || |    ||                                   |     ||                                   ||
                                                                                            \    \\  nan         otherwise     /     \\  nan         otherwise     // \    \\  nan             otherwise        /     \\  nan             otherwise        //
$$\left(\operatorname{re}{\left(\begin{cases} - 4 a - 1 & \text{for}\: a \leq \frac{1}{4} \wedge a > - \frac{3}{4} \\\text{NaN} & \text{otherwise} \end{cases}\right)} + i \operatorname{im}{\left(\begin{cases} - 4 a - 1 & \text{for}\: a \leq \frac{1}{4} \wedge a > - \frac{3}{4} \\\text{NaN} & \text{otherwise} \end{cases}\right)}\right) \left(\operatorname{re}{\left(\begin{cases} - \frac{5}{2 a - 1} & \text{for}\: \frac{5}{2 a - 1} \leq -2 \\\text{NaN} & \text{otherwise} \end{cases}\right)} + i \operatorname{im}{\left(\begin{cases} - \frac{5}{2 a - 1} & \text{for}\: \frac{5}{2 a - 1} \leq -2 \\\text{NaN} & \text{otherwise} \end{cases}\right)}\right) \left(\operatorname{re}{\left(\begin{cases} \frac{1}{2 a - 1} & \text{for}\: a > \frac{1}{4} \wedge a < \frac{1}{2} \\\text{NaN} & \text{otherwise} \end{cases}\right)} + i \operatorname{im}{\left(\begin{cases} \frac{1}{2 a - 1} & \text{for}\: a > \frac{1}{4} \wedge a < \frac{1}{2} \\\text{NaN} & \text{otherwise} \end{cases}\right)}\right)$$
=
nan
$$\text{NaN}$$
nan
Rapid solution [src]
         //-1 - 4*a  for And(a <= 1/4, a > -3/4)\     //-1 - 4*a  for And(a <= 1/4, a > -3/4)\
x1 = I*im|<                                     | + re|<                                     |
         \\  nan              otherwise         /     \\  nan              otherwise         /
$$x_{1} = \operatorname{re}{\left(\begin{cases} - 4 a - 1 & \text{for}\: a \leq \frac{1}{4} \wedge a > - \frac{3}{4} \\\text{NaN} & \text{otherwise} \end{cases}\right)} + i \operatorname{im}{\left(\begin{cases} - 4 a - 1 & \text{for}\: a \leq \frac{1}{4} \wedge a > - \frac{3}{4} \\\text{NaN} & \text{otherwise} \end{cases}\right)}$$
         //  -5             5          \     //  -5             5          \
         ||--------  for -------- <= -2|     ||--------  for -------- <= -2|
x2 = I*im|<-1 + 2*a      -1 + 2*a      | + re|<-1 + 2*a      -1 + 2*a      |
         ||                            |     ||                            |
         \\  nan         otherwise     /     \\  nan         otherwise     /
$$x_{2} = \operatorname{re}{\left(\begin{cases} - \frac{5}{2 a - 1} & \text{for}\: \frac{5}{2 a - 1} \leq -2 \\\text{NaN} & \text{otherwise} \end{cases}\right)} + i \operatorname{im}{\left(\begin{cases} - \frac{5}{2 a - 1} & \text{for}\: \frac{5}{2 a - 1} \leq -2 \\\text{NaN} & \text{otherwise} \end{cases}\right)}$$
         //   1                               \     //   1                               \
         ||--------  for And(a > 1/4, a < 1/2)|     ||--------  for And(a > 1/4, a < 1/2)|
x3 = I*im|<-1 + 2*a                           | + re|<-1 + 2*a                           |
         ||                                   |     ||                                   |
         \\  nan             otherwise        /     \\  nan             otherwise        /
$$x_{3} = \operatorname{re}{\left(\begin{cases} \frac{1}{2 a - 1} & \text{for}\: a > \frac{1}{4} \wedge a < \frac{1}{2} \\\text{NaN} & \text{otherwise} \end{cases}\right)} + i \operatorname{im}{\left(\begin{cases} \frac{1}{2 a - 1} & \text{for}\: a > \frac{1}{4} \wedge a < \frac{1}{2} \\\text{NaN} & \text{otherwise} \end{cases}\right)}$$
x3 = re(Piecewise((1/(2*a - 1, (a > 1/4) & (a < 1/2)), (nan, True))) + i*im(Piecewise((1/(2*a - 1), (a > 1/4) & (a < 1/2)), (nan, True))))