In order to solve the equation, we must square root both sides. We must not forget that we also get a negative solution, since the product of two negative numbers is positive.
Both x=-9 and x=9 are solutions to the equation.
Before we square root the equation, we need to isolate the x2-term on one side.
We can take the square root before adding 3 or before dividing by 2. However, the solution becomes a bit more complicated. Let's square root the equation before dividing by 2. We must keep in mind that we must square root the entire LHS.
We still end up with the same result, even though the process was more complicated.
First we will square root both sides.
Both x=-90 and x=90 are solutions to the equation. If we want to, we can simplify the right side further, so that we get a smaller number under the root sign.