We bought a total of 80 books at the store. Math books cost $4 and history books cost $5. The total price was $373. How many math books did we buy?  Choose the correct choice
A) 23	B) 27	C) 31	D) 35	E) 39

Rationale: "m + h = 80 h = 80 - m 4 m + 5 h = 373 4 m + 5 * ( 80 - m ) = 373 m = 27 the answer is b ."
Answer: B