9x-(7x+5)9x=

Solution for 9x-(7x+5)9x= equation:

9x-(7x+5)9x=

We move all terms to the left:

9x-(7x+5)9x-()=0

We add all the numbers together, and all the variables

9x-(7x+5)9x=0

We multiply parentheses

-63x^2+9x-45x=0

We add all the numbers together, and all the variables

-63x^2-36x=0

a = -63; b = -36; c = 0;
Δ = b2-4ac
Δ = -362-4·(-63)·0
Δ = 1296
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1296}=36$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-36)-36}{2*-63}=\frac{0}{-126}
=0
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-36)+36}{2*-63}=\frac{72}{-126}
=-4/7
$