Recognize equation form: Recognize the equation form. 81=t2 is a basic quadratic equation where t2 means t squared.
Isolate t: Isolate t by taking the square root of both sides.81=t2
Calculate square root: Calculate the square root. 81=9, because 9×9=81. t2=t, because the square root and the square cancel each other out.
Remember two solutions: Remember, there are two solutions for t when you take the square root of a square.t=9 or t=−9, because both 92 and (−9)2 equal 81.
More problems from Solve equations using square roots