13x2+13x+9x+9=0

Solution for 13x2+13x+9x+9=0 equation:

13x^2+13x+9x+9=0

We add all the numbers together, and all the variables

13x^2+22x+9=0

a = 13; b = 22; c = +9;
Δ = b2-4ac
Δ = 222-4·13·9
Δ = 16
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{16}=4$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(22)-4}{2*13}=\frac{-26}{26}
=-1
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(22)+4}{2*13}=\frac{-18}{26}
=-9/13
$