Answer: 4 science and 2 math books
Explanation:
Let M and S stand for the numbers of math and science books.
We know that M+S = 6 books
and M*80 + S*50 = $360
Rearance the first: M = 6-S
Use this definition of M in the second equation:
(6-S)*80 + S*50 = $360
480-80S + 50S = 360
-30S = - 120
S = 4
Use S=4 in the first equation (M=6-S) to find the number of math books, 2.
Check to see if there number work:
4*($50)= $200
2*($80)= $320160
Total is $360. It works.