25a^2+4=-25a

Solution for 25a^2+4=-25a equation:

25a^2+4=-25a

We move all terms to the left:

25a^2+4-(-25a)=0

We get rid of parentheses

25a^2+25a+4=0

a = 25; b = 25; c = +4;
Δ = b2-4ac
Δ = 252-4·25·4
Δ = 225
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{225}=15$
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(25)-15}{2*25}=\frac{-40}{50}
=-4/5
$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(25)+15}{2*25}=\frac{-10}{50}
=-1/5
$