X*(x+7)=17

Solution for X*(x+7)=17 equation:

X(X+7)=17

We move all terms to the left:

X(X+7)-(17)=0

We multiply parentheses

X^2+7X-17=0

a = 1; b = 7; c = -17;
Δ = b2-4ac
Δ = 72-4·1·(-17)
Δ = 117
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:

$\sqrt{\Delta}=\sqrt{117}=\sqrt{9*13}=\sqrt{9}*\sqrt{13}=3\sqrt{13}$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(7)-3\sqrt{13}}{2*1}=\frac{-7-3\sqrt{13}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(7)+3\sqrt{13}}{2*1}=\frac{-7+3\sqrt{13}}{2}
$