13=5x^2-35x+73

Solution for 13=5x^2-35x+73 equation:

13=5x^2-35x+73

We move all terms to the left:

13-(5x^2-35x+73)=0

We get rid of parentheses

-5x^2+35x-73+13=0

We add all the numbers together, and all the variables

-5x^2+35x-60=0

a = -5; b = 35; c = -60;
Δ = b2-4ac
Δ = 352-4·(-5)·(-60)
Δ = 25
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{25}=5$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(35)-5}{2*-5}=\frac{-40}{-10}
=+4
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(35)+5}{2*-5}=\frac{-30}{-10}
=+3
$