Question

Ten bagels and four muffins cost $13. Five bagels and eight muffins cost $14. How much does a bagel cost? How much does a muffin cost?

Answer 1

10b + 4m = 13....multiply by -2
5b + 8m = 14
------------------
-20b - 8m = - 26 (result of multiplying by -2)
5b + 8m = 14
-----------------add
-15b = - 12
b = -12/-15
b = 0.80 <=== bagels cost 0.80 each....80 cents each

10b + 4m = 13
10(0.80) + 4m = 13
8 + 4m = 13
4m = 13 - 8
4m = 5
m = 5/4
m = 1.25 <== muffins cost 1.25 each