e = expresso
m = muffins
2e + 3m = 10.....multiply by -2
4e + 2m = 12
----------------
-4e - 6m = -20 (result of multiplying by -2)
4e + 2m = 12
------------------add
-4m = -8
m = -8/-4
m = 2....so muffins cost $ 2 a piece <===
4e + 2m = 12
4e + 2(2) = 12
4e + 4 = 12
4e = 12 - 4
4e = 8
e = 8/4
e = 2......so expresso's cost $ 2 a piece <===
