Question

a text book store sold a combined total of 411 psychology and math textbooks in a week. the number of math textbooks sold was 63 less than the number of psychology textbooks sold. how many textbooks of each typer were sold

Answer 1

psychology textbook = P = 237
math textbook = M = 174
P+M=411
M=P-63 (rearrange to make P-M=63)
Line up and add (3)
P=237, M= 174