Answer:
89
Step-by-step explanation:
Given that Wendy took 2 tests and scored, 77 and 80 respectively, let x represent the grade of Wendy's third test.
To get an average grade of 82, let's generate an equation to find x (Wendy's grade on her third test).
Average grade = sum of all 3 grades all over 3
Multiply 3 by both sides
Subtract 157 from each side of the equation
Wendy must score 89 on her third test to have an average of 82.