Firstly it's not a radical expression.
You can factorize the numerator x²+12x+36 = (x+6)²
Factorize the denominator 12x+72 = 12(x+6)
=(x+6)² / 12(x+6) , simplify. Answer = (x+6)/12
<span>x^2 - 4x - 12 = 0
factors
(x - 6)(x + 2) = 0
</span>Set (x - 6) and (x + 2)<span> equal to </span><span>0</span><span> and solve for </span><span>xx</span>.<span>
x - 6 = 0; x = 6
x + 2 = 0; x = -2
answer
x = -2 or x = 6</span>
