X2+4x=15-(-x-6)

Solution for X2+4x=15-(-x-6) equation:

X2+4X=15-(-X-6)

We move all terms to the left:

X2+4X-(15-(-X-6))=0

We add all the numbers together, and all the variables

X2+4X-(15-(-1X-6))=0

We add all the numbers together, and all the variables

X^2+4X-(15-(-1X-6))=0


We calculate terms in parentheses: -(15-(-1X-6)), so:

15-(-1X-6)

determiningTheFunctionDomain
-(-1X-6)+15

We get rid of parentheses

1X+6+15

We add all the numbers together, and all the variables

X+21

Back to the equation:

-(X+21)


We get rid of parentheses

X^2+4X-X-21=0

We add all the numbers together, and all the variables

X^2+3X-21=0

a = 1; b = 3; c = -21;
Δ = b2-4ac
Δ = 32-4·1·(-21)
Δ = 93
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{-(3)-\sqrt{93}}{2*1}=\frac{-3-\sqrt{93}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(3)+\sqrt{93}}{2*1}=\frac{-3+\sqrt{93}}{2}
$