Question

i buy 3 pineapples and 2 melons for $34 and my friend buys 2 pineapples and 4 melons for $36. how much do the pineapples and melons cost

Answer 1

The cost of 1 pineapple is $ 8 and cost of 1 melon is $ 5

Solution:

Let "x" be the cost of 1 pineapple

Let "y" be the cost of 1 melon

3 pineapples and 2 melons for $34

Therefore,

3x + 2y = 34 -------- eqn 1

my friend buys 2 pineapples and 4 melons for $36

Therefore,

2x + 4y = 36 --- eqn 2

Let us solve eqn 1 and eqn 2

Multiply eqn 1 by -2

-6x -4y = -68 -------- eqn 3

Add eqn 2 and eqn 3

2x + 4y = 36

-6x -4y = -68

( + ) -------------

-4x = -32

x = 8

Substitute x = 8 in eqn 1

3(8) + 2y = 34

2y = 34 - 24

2y = 10

y = 5

Thus cost of 1 pineapple is $ 8 and cost of 1 melon is $ 5