4u(2u+7)=0

Solution for 4u(2u+7)=0 equation:

4u(2u+7)=0

We multiply parentheses

8u^2+28u=0

a = 8; b = 28; c = 0;
Δ = b2-4ac
Δ = 282-4·8·0
Δ = 784
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$u_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$u_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{784}=28$
$u_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(28)-28}{2*8}=\frac{-56}{16}
=-3+1/2
$
$u_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(28)+28}{2*8}=\frac{0}{16}
=0
$