7y2+18y+-8=0

Solution for 7y2+18y+-8=0 equation:

7y^2+18y+-8=0

We add all the numbers together, and all the variables

7y^2+18y=0

a = 7; b = 18; c = 0;
Δ = b2-4ac
Δ = 182-4·7·0
Δ = 324
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{324}=18$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(18)-18}{2*7}=\frac{-36}{14}
=-2+4/7
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(18)+18}{2*7}=\frac{0}{14}
=0
$