25x^2+20x+4=9

Solution for 25x^2+20x+4=9 equation:

25x^2+20x+4=9

We move all terms to the left:

25x^2+20x+4-(9)=0

We add all the numbers together, and all the variables

25x^2+20x-5=0

a = 25; b = 20; c = -5;
Δ = b2-4ac
Δ = 202-4·25·(-5)
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{-(20)-30}{2*25}=\frac{-50}{50}
=-1
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(20)+30}{2*25}=\frac{10}{50}
=1/5
$