(3x+6)(2x+5)=30

Solution for (3x+6)(2x+5)=30 equation:

(3x+6)(2x+5)=30

We move all terms to the left:

(3x+6)(2x+5)-(30)=0

We multiply parentheses ..

(+6x^2+15x+12x+30)-30=0

We get rid of parentheses

6x^2+15x+12x+30-30=0

We add all the numbers together, and all the variables

6x^2+27x=0

a = 6; b = 27; c = 0;
Δ = b2-4ac
Δ = 272-4·6·0
Δ = 729
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{729}=27$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(27)-27}{2*6}=\frac{-54}{12}
=-4+1/2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(27)+27}{2*6}=\frac{0}{12}
=0
$