x(x+6)=7(7+9)

Solution for x(x+6)=7(7+9) equation:

x(x+6)=7(7+9)

We move all terms to the left:

x(x+6)-(7(7+9))=0

We add all the numbers together, and all the variables

x(x+6)-(716)=0

We add all the numbers together, and all the variables

x(x+6)-716=0

We multiply parentheses

x^2+6x-716=0

a = 1; b = 6; c = -716;
Δ = b2-4ac
Δ = 62-4·1·(-716)
Δ = 2900
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:

$\sqrt{\Delta}=\sqrt{2900}=\sqrt{100*29}=\sqrt{100}*\sqrt{29}=10\sqrt{29}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(6)-10\sqrt{29}}{2*1}=\frac{-6-10\sqrt{29}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(6)+10\sqrt{29}}{2*1}=\frac{-6+10\sqrt{29}}{2}
$