Find roots of polynomial $$ p(x) = -x^2+8x $$

The roots of polynomial $ p(x) $ are:

$$ \begin{aligned}x_1 &= 0\\[1 em]x_2 &= 8 \end{aligned} $$

Step 1:

Factor out $ \color{blue}{ -x }$ from $ -x^2+8x $ and solve two separate equations:

$$ \begin{aligned} -x^2+8x & = 0\\[1 em] \color{blue}{ -x }\cdot ( x-8 ) & = 0 \\[1 em] \color{blue}{ -x = 0} ~~ \text{or} ~~ x-8 & = 0 \end{aligned} $$

One solution is $ \color{blue}{ x = 0 } $. Use second equation to find the remaining roots.

Step 2:

To find the second zero, solve equation $ x-8 = 0 $

$$ \begin{aligned} x-8 & = 0 \\[1 em] x & = 8 \end{aligned} $$

Polynomial Roots Calculator