Suppose you got 8 mangoes and 3 apples for $18 and 3 mangoes and 5 apples for $14.50. How many does each mango and each apple cost?

M = mangoes

a = apples

8m + 3a = 18 Equation 1

3m + 5a = 14.50 Equation 2

Lets multiply equation 1 by 5 and equation 2 by 3

The new equations are:

45m + 15a = 90

9m + 15a = 43.5

Subtract them and get:

36m = 46.5

m = 1.30 Divide both sides by 36

Substitute m into equation 2 (either is fine, but choose the easier one)

3 (1.30) + 5a = 14.5

3.9 + 5a = 14.6 Expand the bracket

5a = 10.6 Minus both sides by 3.9

a = 2.12 Divide both sides by 5

Mangoes cost $1.30

Apples cost $2.12 (more like $2.10)

I feel that my working out is wrong, but that is how you work out the answer.