X+2x(x+3)=36

Solution for X+2x(x+3)=36 equation:

X+2X(X+3)=36

We move all terms to the left:

X+2X(X+3)-(36)=0

We multiply parentheses

2X^2+X+6X-36=0

We add all the numbers together, and all the variables

2X^2+7X-36=0

a = 2; b = 7; c = -36;
Δ = b2-4ac
Δ = 72-4·2·(-36)
Δ = 337
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{-(7)-\sqrt{337}}{2*2}=\frac{-7-\sqrt{337}}{4}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(7)+\sqrt{337}}{2*2}=\frac{-7+\sqrt{337}}{4}
$