(5x+2)(5x+2)=49

Solution for (5x+2)(5x+2)=49 equation:

(5x+2)(5x+2)=49

We move all terms to the left:

(5x+2)(5x+2)-(49)=0

We multiply parentheses ..

(+25x^2+10x+10x+4)-49=0

We get rid of parentheses

25x^2+10x+10x+4-49=0

We add all the numbers together, and all the variables

25x^2+20x-45=0

a = 25; b = 20; c = -45;
Δ = b2-4ac
Δ = 202-4·25·(-45)
Δ = 4900
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4900}=70$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(20)-70}{2*25}=\frac{-90}{50}
=-1+4/5
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(20)+70}{2*25}=\frac{50}{50}
=1
$