-9=4X2+16x-9

Solution for -9=4X2+16x-9 equation:

-9=4X^2+16X-9

We move all terms to the left:

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

We get rid of parentheses

-4X^2-16X+9-9=0

We add all the numbers together, and all the variables

-4X^2-16X=0

a = -4; b = -16; c = 0;
Δ = b2-4ac
Δ = -162-4·(-4)·0
Δ = 256
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{256}=16$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-16)-16}{2*-4}=\frac{0}{-8}
=0
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-16)+16}{2*-4}=\frac{32}{-8}
=-4
$