(7x-7)(5x-3)=180

Solution for (7x-7)(5x-3)=180 equation:

(7x-7)(5x-3)=180

We move all terms to the left:

(7x-7)(5x-3)-(180)=0

We multiply parentheses ..

(+35x^2-21x-35x+21)-180=0

We get rid of parentheses

35x^2-21x-35x+21-180=0

We add all the numbers together, and all the variables

35x^2-56x-159=0

a = 35; b = -56; c = -159;
Δ = b2-4ac
Δ = -562-4·35·(-159)
Δ = 25396
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{25396}=\sqrt{4*6349}=\sqrt{4}*\sqrt{6349}=2\sqrt{6349}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-56)-2\sqrt{6349}}{2*35}=\frac{56-2\sqrt{6349}}{70}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-56)+2\sqrt{6349}}{2*35}=\frac{56+2\sqrt{6349}}{70}
$