the cost of a magazine and 2 books is $34. the cost of 3 magazines and 4 books $76. (more in description)

Question

if tasha buys 13 magazines and 9 books, how much money does she spend?

please show working.

Answer 1

M + 2B = 34

3M + 4B = 76

multiply 1st equation by 2 and subtract from the 2nd equation to eliminate 1 variable

2M + 4B = 34(2) = 68

3M-2M = M = 76-68= $8 for a magazine

2B =34-8= 26

B = 26/2 = $13 for a book

13M + 9B = 13(8)+9(13) = 104 + 117 = $221 for 13 magazines and 9 books