-9u-2=-4u^2

Solution for -9u-2=-4u^2 equation:

-9u-2=-4u^2

We move all terms to the left:

-9u-2-(-4u^2)=0

We get rid of parentheses

4u^2-9u-2=0

a = 4; b = -9; c = -2;
Δ = b2-4ac
Δ = -92-4·4·(-2)
Δ = 113
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$u_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$u_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$u_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-9)-\sqrt{113}}{2*4}=\frac{9-\sqrt{113}}{8}
$
$u_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-9)+\sqrt{113}}{2*4}=\frac{9+\sqrt{113}}{8}
$