5x(x+20)=7x+30

Solution for 5x(x+20)=7x+30 equation:

5x(x+20)=7x+30

We move all terms to the left:

5x(x+20)-(7x+30)=0

We multiply parentheses

5x^2+100x-(7x+30)=0

We get rid of parentheses

5x^2+100x-7x-30=0

We add all the numbers together, and all the variables

5x^2+93x-30=0

a = 5; b = 93; c = -30;
Δ = b2-4ac
Δ = 932-4·5·(-30)
Δ = 9249
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(93)-\sqrt{9249}}{2*5}=\frac{-93-\sqrt{9249}}{10}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(93)+\sqrt{9249}}{2*5}=\frac{-93+\sqrt{9249}}{10}
$