100r2+7=8

Solution for 100r2+7=8 equation:

100r^2+7=8

We move all terms to the left:

100r^2+7-(8)=0

We add all the numbers together, and all the variables

100r^2-1=0

a = 100; b = 0; c = -1;
Δ = b2-4ac
Δ = 02-4·100·(-1)
Δ = 400
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{400}=20$
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-20}{2*100}=\frac{-20}{200}
=-1/10
$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+20}{2*100}=\frac{20}{200}
=1/10
$