7-4=4y*(8-6)-64

Solution for 7-4=4y*(8-6)-64 equation:

7-4=4y(8-6)-64

We move all terms to the left:

7-4-(4y(8-6)-64)=0

We add all the numbers together, and all the variables

-(4y2-64)+7-4=0

We add all the numbers together, and all the variables

-(4y2-64)+3=0

We get rid of parentheses

-4y2+64+3=0

We add all the numbers together, and all the variables

-4y^2+67=0

a = -4; b = 0; c = +67;
Δ = b2-4ac
Δ = 02-4·(-4)·67
Δ = 1072
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{1072}=\sqrt{16*67}=\sqrt{16}*\sqrt{67}=4\sqrt{67}$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-4\sqrt{67}}{2*-4}=\frac{0-4\sqrt{67}}{-8}
=-\frac{4\sqrt{67}}{-8}
=-\frac{\sqrt{67}}{-2}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+4\sqrt{67}}{2*-4}=\frac{0+4\sqrt{67}}{-8}
=\frac{4\sqrt{67}}{-8}
=\frac{\sqrt{67}}{-2}
$