Answer: {11, -11}
Step-by-step-explanation: To solve for x in this equation, since x is squared, we simply take the square root of both sides of the equation to get x by itself.
It's important to remember however that when taking the square root of both sides of an equation, we always use plus or minus.
In other words in this problem, since x² = 121,
x = + or - 11.
A common mistake is to say that x is just equal to 11. But notice that if you plug a -11 back into the original equation, it also checks.
So our answer to this problem is {11, -11}.