7x+|-10+2x|x=-4 equation
The teacher will be very surprised to see your correct solution 😉
The solution
Detail solution
For every modulo expressions in the equation
allow cases, when this expressions ">=0" or "<0",
solve the resulting equation.
1.
$$2 x - 10 \geq 0$$
or
$$5 \leq x \wedge x < \infty$$
we get the equation
$$x \left(2 x - 10\right) + 7 x + 4 = 0$$
after simplifying we get
$$x \left(2 x - 10\right) + 7 x + 4 = 0$$
the solution in this interval:
$$x_{1} = \frac{3}{4} - \frac{\sqrt{23} i}{4}$$
but x1 not in the inequality interval
$$x_{2} = \frac{3}{4} + \frac{\sqrt{23} i}{4}$$
but x2 not in the inequality interval
2.
$$2 x - 10 < 0$$
or
$$-\infty < x \wedge x < 5$$
we get the equation
$$x \left(10 - 2 x\right) + 7 x + 4 = 0$$
after simplifying we get
$$x \left(10 - 2 x\right) + 7 x + 4 = 0$$
the solution in this interval:
$$x_{3} = \frac{17}{4} - \frac{\sqrt{321}}{4}$$
$$x_{4} = \frac{17}{4} + \frac{\sqrt{321}}{4}$$
but x4 not in the inequality interval
The final answer:
$$x_{1} = \frac{17}{4} - \frac{\sqrt{321}}{4}$$
Sum and product of roots
[src]
_____
17 \/ 321
-- - -------
4 4
$$\frac{17}{4} - \frac{\sqrt{321}}{4}$$
_____
17 \/ 321
-- - -------
4 4
$$\frac{17}{4} - \frac{\sqrt{321}}{4}$$
_____
17 \/ 321
-- - -------
4 4
$$\frac{17}{4} - \frac{\sqrt{321}}{4}$$
_____
17 \/ 321
-- - -------
4 4
$$\frac{17}{4} - \frac{\sqrt{321}}{4}$$
_____
17 \/ 321
x1 = -- - -------
4 4
$$x_{1} = \frac{17}{4} - \frac{\sqrt{321}}{4}$$