(2u+7)(9+u)=0

Solution for (2u+7)(9+u)=0 equation:

(2u+7)(9+u)=0

We add all the numbers together, and all the variables

(2u+7)(u+9)=0

We multiply parentheses ..

(+2u^2+18u+7u+63)=0

We get rid of parentheses

2u^2+18u+7u+63=0

We add all the numbers together, and all the variables

2u^2+25u+63=0

a = 2; b = 25; c = +63;
Δ = b2-4ac
Δ = 252-4·2·63
Δ = 121
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$u_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$u_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{121}=11$
$u_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(25)-11}{2*2}=\frac{-36}{4}
=-9
$
$u_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(25)+11}{2*2}=\frac{-14}{4}
=-3+1/2
$