3x(5x+5)=3(5x+5)

Solution for 3x(5x+5)=3(5x+5) equation:

3x(5x+5)=3(5x+5)

We move all terms to the left:

3x(5x+5)-(3(5x+5))=0

We multiply parentheses

15x^2+15x-(3(5x+5))=0


We calculate terms in parentheses: -(3(5x+5)), so:

3(5x+5)

We multiply parentheses

15x+15

Back to the equation:

-(15x+15)


We get rid of parentheses

15x^2+15x-15x-15=0

We add all the numbers together, and all the variables

15x^2-15=0

a = 15; b = 0; c = -15;
Δ = b2-4ac
Δ = 02-4·15·(-15)
Δ = 900
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{900}=30$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-30}{2*15}=\frac{-30}{30}
=-1
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+30}{2*15}=\frac{30}{30}
=1
$