.(-7s+4)-(-8s+4)=

Solution for .(-7s+4)-(-8s+4)= equation:

.(-7s+4)-(-8s+4)=

We move all terms to the left:

.(-7s+4)-(-8s+4)-()=0

We add all the numbers together, and all the variables

.(-7s+4)-(-8s+4)=0

We multiply parentheses

-7s^2-(-8s+4)+=0

We get rid of parentheses

-7s^2+8s-4+=0

We add all the numbers together, and all the variables

-7s^2+8s=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:
$s_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$s_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

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