$$7z^2+4z-(2z^2-4z) = 0$$
Answer
$$ \begin{matrix}z_1 = 0 & z_2 = -\dfrac{ 8 }{ 5 } \\[1 em] \end{matrix} $$
Explanation
$$ \begin{aligned} 7z^2+4z-(2z^2-4z) &= 0&& \text{simplify left side} \\[1 em]7z^2+4z-2z^2+4z &= 0&& \\[1 em]5z^2+8z &= 0&& \\[1 em] \end{aligned} $$
In order to solve $ \color{blue}{ 5x^{2}+8x = 0 } $, first we need to factor our $ x $.
$$ 5x^{2}+8x = x \left( 5x+8 \right) $$$ x = 0 $ is a root of multiplicity $ 1 $.
The second root can be found by solving equation $ 5x+8 = 0$.
This page was created using
Polynomial Equations Solver