word problems in Algebra

Question

A student in an algebra course has test scores of 71, 83, 79, and 84. What score on the next test will raise the student's average to 82?

Answer 1

the current average of 4 scores is (71+83+79+84)/4 = 79 1/4

to get an average of 82 (71+83+79+84+ X)/4 = 82 x 5

or 317 + X = 82(5) = 410

X = 410-317 = 93 for the 5th score to raise the average to 82