(3w+8)(7w-9)=

Solution for (3w+8)(7w-9)= equation:

(3w+8)(7w-9)=

We move all terms to the left:

(3w+8)(7w-9)-()=0

We add all the numbers together, and all the variables

(3w+8)(7w-9)=0

We multiply parentheses ..

(+21w^2-27w+56w-72)=0

We get rid of parentheses

21w^2-27w+56w-72=0

We add all the numbers together, and all the variables

21w^2+29w-72=0

a = 21; b = 29; c = -72;
Δ = b2-4ac
Δ = 292-4·21·(-72)
Δ = 6889
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$w_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$w_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{6889}=83$
$w_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(29)-83}{2*21}=\frac{-112}{42}
=-2+2/3
$
$w_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(29)+83}{2*21}=\frac{54}{42}
=1+2/7
$