Question

A textbook store sold a combined total of 257 math and psychology textbooks in a week. The number of math textbooks sold was 87 more than the number of psychology textbooks sold. How many textbooks of each type were sold?

Answer 1

Answer:

• 85 psychology
• 172 math

Step-by-step explanation:

Let p represent the number of psychology textbooks sold. Then the total number sold was ...

  p + (p+87) = 257

  2p = 170 . . . . . .subtract 87; next divide by 2

  p = 85 . . . . . . . psychology books sold

  p+87 = 172 . . . math books sold