-4(-7+y)3y=23

Solution for -4(-7+y)3y=23 equation:

-4(-7+y)3y=23

We move all terms to the left:

-4(-7+y)3y-(23)=0

We add all the numbers together, and all the variables

-4(y-7)3y-23=0

We multiply parentheses

-12y^2+84y-23=0

a = -12; b = 84; c = -23;
Δ = b2-4ac
Δ = 842-4·(-12)·(-23)
Δ = 5952
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:

$\sqrt{\Delta}=\sqrt{5952}=\sqrt{64*93}=\sqrt{64}*\sqrt{93}=8\sqrt{93}$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(84)-8\sqrt{93}}{2*-12}=\frac{-84-8\sqrt{93}}{-24}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(84)+8\sqrt{93}}{2*-12}=\frac{-84+8\sqrt{93}}{-24}
$