$$x(x+2) = 140$$
Answer
$$ \begin{matrix}x_1 = -1-\sqrt{ 141 } & x_2 = -1+\sqrt{ 141 } \\[1 em] \end{matrix} $$
Explanation
$$ \begin{aligned} x(x+2) &= 140&& \text{simplify left side} \\[1 em]x^2+2x &= 140&& \text{move all terms to the left hand side } \\[1 em]x^2+2x-140 &= 0&& \\[1 em] \end{aligned} $$
$ x^{2}+2x-140 = 0 $ is a quadratic equation.
You can use step-by-step quadratic equation solver to see a detailed explanation on how to solve this equation.
This page was created using
Polynomial Equations Solver