Given the inequality:
$$\frac{14 x^{2}}{5} + \frac{311 x}{50} - \frac{13}{2} < - \frac{x^{2}}{5} - \frac{89 x}{50} + \frac{9}{2}$$
To solve this inequality, we must first solve the corresponding equation:
$$\frac{14 x^{2}}{5} + \frac{311 x}{50} - \frac{13}{2} = - \frac{x^{2}}{5} - \frac{89 x}{50} + \frac{9}{2}$$
Solve:
Move right part of the equation to
left part with negative sign.
The equation is transformed from
$$\frac{14 x^{2}}{5} + \frac{311 x}{50} - \frac{13}{2} = - \frac{x^{2}}{5} - \frac{89 x}{50} + \frac{9}{2}$$
to
$$\left(\frac{x^{2}}{5} + \frac{89 x}{50} - \frac{9}{2}\right) + \left(\frac{14 x^{2}}{5} + \frac{311 x}{50} - \frac{13}{2}\right) = 0$$
Expand the expression in the equation
$$\left(\frac{x^{2}}{5} + \frac{89 x}{50} - \frac{9}{2}\right) + \left(\frac{14 x^{2}}{5} + \frac{311 x}{50} - \frac{13}{2}\right) = 0$$
We get the quadratic equation
$$3 x^{2} + 8 x - 11 = 0$$
This equation is of the form
a*x^2 + b*x + c = 0
A quadratic equation can be solved
using the discriminant.
The roots of the quadratic equation:
$$x_{1} = \frac{\sqrt{D} - b}{2 a}$$
$$x_{2} = \frac{- \sqrt{D} - b}{2 a}$$
where D = b^2 - 4*a*c - it is the discriminant.
Because
$$a = 3$$
$$b = 8$$
$$c = -11$$
, then
D = b^2 - 4 * a * c =
(8)^2 - 4 * (3) * (-11) = 196
Because D > 0, then the equation has two roots.
x1 = (-b + sqrt(D)) / (2*a)
x2 = (-b - sqrt(D)) / (2*a)
or
$$x_{1} = 1$$
Simplify$$x_{2} = - \frac{11}{3}$$
Simplify$$x_{1} = 1$$
$$x_{2} = - \frac{11}{3}$$
$$x_{1} = 1$$
$$x_{2} = - \frac{11}{3}$$
This roots
$$x_{2} = - \frac{11}{3}$$
$$x_{1} = 1$$
is the points with change the sign of the inequality expression.
First define with the sign to the leftmost point:
$$x_{0} < x_{2}$$
For example, let's take the point
$$x_{0} = x_{2} - \frac{1}{10}$$
=
$$- \frac{11}{3} - \frac{1}{10}$$
=
$$- \frac{113}{30}$$
substitute to the expression
$$\frac{14 x^{2}}{5} + \frac{311 x}{50} - \frac{13}{2} < - \frac{x^{2}}{5} - \frac{89 x}{50} + \frac{9}{2}$$
$$\frac{311}{50} \left(- \frac{113}{30}\right) - \frac{13}{2} + \frac{14 \left(- \frac{113}{30}\right)^{2}}{5} < - \frac{\left(- \frac{113}{30}\right)^{2}}{5} + \frac{9}{2} - \frac{89}{50} \left(- \frac{113}{30}\right)$$
44087 9413
----- < ----
4500 1125
but
44087 9413
----- > ----
4500 1125
Then
$$x < - \frac{11}{3}$$
no execute
one of the solutions of our inequality is:
$$x > - \frac{11}{3} \wedge x < 1$$
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x_2 x_1