16n^2+40n+25=9

Solution for 16n^2+40n+25=9 equation:

16n^2+40n+25=9

We move all terms to the left:

16n^2+40n+25-(9)=0

We add all the numbers together, and all the variables

16n^2+40n+16=0

a = 16; b = 40; c = +16;
Δ = b2-4ac
Δ = 402-4·16·16
Δ = 576
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{576}=24$
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(40)-24}{2*16}=\frac{-64}{32}
=-2
$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(40)+24}{2*16}=\frac{-16}{32}
=-1/2
$