(w+5)(w-2)=10

Solution for (w+5)(w-2)=10 equation:

(w+5)(w-2)=10

We move all terms to the left:

(w+5)(w-2)-(10)=0

We multiply parentheses ..

(+w^2-2w+5w-10)-10=0

We get rid of parentheses

w^2-2w+5w-10-10=0

We add all the numbers together, and all the variables

w^2+3w-20=0

a = 1; b = 3; c = -20;
Δ = b2-4ac
Δ = 32-4·1·(-20)
Δ = 89
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$w_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$w_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$w_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(3)-\sqrt{89}}{2*1}=\frac{-3-\sqrt{89}}{2}
$
$w_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(3)+\sqrt{89}}{2*1}=\frac{-3+\sqrt{89}}{2}
$