7x-9x2=5x-9

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Solution for 7x-9x2=5x-9 equation:



7x-9x^2=5x-9
We move all terms to the left:
7x-9x^2-(5x-9)=0
We get rid of parentheses
-9x^2+7x-5x+9=0
We add all the numbers together, and all the variables
-9x^2+2x+9=0
a = -9; b = 2; c = +9;
Δ = b2-4ac
Δ = 22-4·(-9)·9
Δ = 328
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:
$\sqrt{\Delta}=\sqrt{328}=\sqrt{4*82}=\sqrt{4}*\sqrt{82}=2\sqrt{82}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(2)-2\sqrt{82}}{2*-9}=\frac{-2-2\sqrt{82}}{-18} $
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(2)+2\sqrt{82}}{2*-9}=\frac{-2+2\sqrt{82}}{-18} $

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