6-(5y-7)y=6

Solution for 6-(5y-7)y=6 equation:

6-(5y-7)y=6

We move all terms to the left:

6-(5y-7)y-(6)=0

We add all the numbers together, and all the variables

-(5y-7)y=0

We multiply parentheses

-5y^2+7y=0

a = -5; b = 7; c = 0;
Δ = b2-4ac
Δ = 72-4·(-5)·0
Δ = 49
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{49}=7$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(7)-7}{2*-5}=\frac{-14}{-10}
=1+2/5
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(7)+7}{2*-5}=\frac{0}{-10}
=0
$