-5x^2+9x=-4

Solution for -5x^2+9x=-4 equation:

-5x^2+9x=-4

We move all terms to the left:

-5x^2+9x-(-4)=0

We add all the numbers together, and all the variables

-5x^2+9x+4=0

a = -5; b = 9; c = +4;
Δ = b2-4ac
Δ = 92-4·(-5)·4
Δ = 161
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(9)-\sqrt{161}}{2*-5}=\frac{-9-\sqrt{161}}{-10}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(9)+\sqrt{161}}{2*-5}=\frac{-9+\sqrt{161}}{-10}
$