-9x+7=25+2(5-x)x=-4

Solution for -9x+7=25+2(5-x)x=-4 equation:

-9x+7=25+2(5-x)x=-4

We move all terms to the left:

-9x+7-(25+2(5-x)x)=0

We add all the numbers together, and all the variables

-9x-(25+2(-1x+5)x)+7=0


We calculate terms in parentheses: -(25+2(-1x+5)x), so:

25+2(-1x+5)x

determiningTheFunctionDomain
2(-1x+5)x+25

We multiply parentheses

-2x^2+10x+25

Back to the equation:

-(-2x^2+10x+25)


We get rid of parentheses

2x^2-10x-9x-25+7=0

We add all the numbers together, and all the variables

2x^2-19x-18=0

a = 2; b = -19; c = -18;
Δ = b2-4ac
Δ = -192-4·2·(-18)
Δ = 505
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-19)-\sqrt{505}}{2*2}=\frac{19-\sqrt{505}}{4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-19)+\sqrt{505}}{2*2}=\frac{19+\sqrt{505}}{4}
$