X.4(x+5)=15-6

Solution for X.4(x+5)=15-6 equation:

X.4(X+5)=15-6

We move all terms to the left:

X.4(X+5)-(15-6)=0

We add all the numbers together, and all the variables

X.4(X+5)-9=0

We multiply parentheses

X^2+5X-9=0

a = 1; b = 5; c = -9;
Δ = b2-4ac
Δ = 52-4·1·(-9)
Δ = 61
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{-(5)-\sqrt{61}}{2*1}=\frac{-5-\sqrt{61}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(5)+\sqrt{61}}{2*1}=\frac{-5+\sqrt{61}}{2}
$