4y2-y=72

Solution for 4y2-y=72 equation:

4y^2-y=72

We move all terms to the left:

4y^2-y-(72)=0

We add all the numbers together, and all the variables

4y^2-1y-72=0

a = 4; b = -1; c = -72;
Δ = b2-4ac
Δ = -12-4·4·(-72)
Δ = 1153
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-1)-\sqrt{1153}}{2*4}=\frac{1-\sqrt{1153}}{8}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1)+\sqrt{1153}}{2*4}=\frac{1+\sqrt{1153}}{8}
$