x(8+7x)=0

Solution for x(8+7x)=0 equation:

x(8+7x)=0

We add all the numbers together, and all the variables

x(7x+8)=0

We multiply parentheses

7x^2+8x=0

a = 7; b = 8; c = 0;
Δ = b2-4ac
Δ = 82-4·7·0
Δ = 64
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{64}=8$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(8)-8}{2*7}=\frac{-16}{14}
=-1+1/7
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(8)+8}{2*7}=\frac{0}{14}
=0
$