Question

i wnet to the grocery store this weekend and bought 3 lbs of apples and 4lbs of oranges for $3.45. if i had bought 4 lbs of apples and 2 lbs of oranges then it would of only cost me $3.10. how much did it cost me per pound for apples and how much per pound of oranges?

Answer 1

apples - $0,55 per pound

oranges - $0,45 per pound

Explanation:

Let's assume, that apples cost x dollars per pound and oranges cost y dollars per pound.

Let's write 2 equations according to the given information and put them in a system:

{3x + 4y = 3,45,

{4x + 2y = 3,10;

Let's make x the subject from the 1st equation:

3x = 3,45 - 4y / : 3

x = 1,15 - 1 1/3y

Let's replace x in the 2nd equation:

`4 *(1.15 - 1 (1)/(3) y) + 2y = 3.10`

`4.6 - (16)/(3) y + 2y = 3.10`

`- (10)/(3) y = 3.10- 4.6`

`- (10)/(3) y = - 1.5`

`y = 0.45`

`x = 1.15 - 1 (1)/(3) * 0.45 = 0.55`