3x^2+4x=64

Solution for 3x^2+4x=64 equation:

3x^2+4x=64

We move all terms to the left:

3x^2+4x-(64)=0

a = 3; b = 4; c = -64;
Δ = b2-4ac
Δ = 42-4·3·(-64)
Δ = 784
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{784}=28$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(4)-28}{2*3}=\frac{-32}{6}
=-5+1/3
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(4)+28}{2*3}=\frac{24}{6}
=4
$