9x^2+16x=4

Solution for 9x^2+16x=4 equation:

9x^2+16x=4

We move all terms to the left:

9x^2+16x-(4)=0

a = 9; b = 16; c = -4;
Δ = b2-4ac
Δ = 162-4·9·(-4)
Δ = 400
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{400}=20$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(16)-20}{2*9}=\frac{-36}{18}
=-2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(16)+20}{2*9}=\frac{4}{18}
=2/9
$