Let's start by recalling how to solve equations that contain a variable that is squared and equal to a non-negative number. These types of equations have two solutions.
x^2=a ⇒ x=± sqrt(a)
This is because both (sqrt(a))^2 and (- sqrt(a))^2 are equal to a. Let's think of a more concrete example.
sqrt(9)=±3 because
3^2=9 and (-3)^2=9
With this in mind, let's solve the given equation.
y^2 = 81
Since y is raised to the second power, we will take the square root of both sides. Let's do it!
