Answer: {11, -11}
Step-by-step-explanation: To solve for <em>x</em> in this equation, since <em>x</em> is squared, we simply take the square root of both sides of the equation to get <em>x</em> by itself.
It's important to remember however that when taking the square root of both sides of an equation, we always use <em><u>plus</u></em> or <em><u>minus</u></em>.
In other words in this problem, since x² = 121,
<em>x = + or - 11</em>.
A common mistake is to say that <em>x</em> 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}.