4u^2+u=15

Solution for 4u^2+u=15 equation:

4u^2+u=15

We move all terms to the left:

4u^2+u-(15)=0

a = 4; b = 1; c = -15;
Δ = b2-4ac
Δ = 12-4·4·(-15)
Δ = 241
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{-(1)-\sqrt{241}}{2*4}=\frac{-1-\sqrt{241}}{8}
$
$u_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(1)+\sqrt{241}}{2*4}=\frac{-1+\sqrt{241}}{8}
$