4x2+4x=77

Solution for 4x2+4x=77 equation:

4x^2+4x=77

We move all terms to the left:

4x^2+4x-(77)=0

a = 4; b = 4; c = -77;
Δ = b2-4ac
Δ = 42-4·4·(-77)
Δ = 1248
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{1248}=\sqrt{16*78}=\sqrt{16}*\sqrt{78}=4\sqrt{78}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(4)-4\sqrt{78}}{2*4}=\frac{-4-4\sqrt{78}}{8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(4)+4\sqrt{78}}{2*4}=\frac{-4+4\sqrt{78}}{8}
$