(2w+7)(5-w)=0

Solution for (2w+7)(5-w)=0 equation:

(2w+7)(5-w)=0

We add all the numbers together, and all the variables

(2w+7)(-1w+5)=0

We multiply parentheses ..

(-2w^2+10w-7w+35)=0

We get rid of parentheses

-2w^2+10w-7w+35=0

We add all the numbers together, and all the variables

-2w^2+3w+35=0

a = -2; b = 3; c = +35;
Δ = b2-4ac
Δ = 32-4·(-2)·35
Δ = 289
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$w_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$w_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{289}=17$
$w_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(3)-17}{2*-2}=\frac{-20}{-4}
=+5
$
$w_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(3)+17}{2*-2}=\frac{14}{-4}
=-3+1/2
$