35-18u-5u^2=0

Solution for 35-18u-5u^2=0 equation:

35-18u-5u^2=0

a = -5; b = -18; c = +35;
Δ = b2-4ac
Δ = -182-4·(-5)·35
Δ = 1024
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$u_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$u_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1024}=32$
$u_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-18)-32}{2*-5}=\frac{-14}{-10}
=1+2/5
$
$u_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-18)+32}{2*-5}=\frac{50}{-10}
=-5
$