So first, let's get rid of the parentheses. We can multiply it out to get . We know that the square root of 16 is ±4, so now our equation is ±4 - =11. I'm guessing since the problem only has one solution it's most likely only positive 4, so let's revise our equation to 4 - =11. We can use inverse operations to make the a little easier to solve: -7= . We divide both sides by to get , which we can rationalize (remove the square root from the denominator so that it's a proper answer) by multiplying by (which is equal to one so we can use it) which is equal to . Let's finish this by simplifying it. (2x). We can simplify it further by simplifying the 2, making it .
Hope this wasn't too confusing! I'll answer any questions.