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Question

A store is having a sale on jelly beans and almonds. For 5 pounds of jelly beans and 3 pounds of almonds, the total cost is $19. For 7 pounds of jelly beans and 9 pounds of almonds, the total cost is $35. Find the cost for each pound of jelly beans and each pound of almonds.

Answer 1

These used to really get me! Here we go!

5j + 3a = 19

7j + 9a = 35

OK, here's the trick: If we multiply the first equation by -3 we'll get -9a which will cancel out with 9a in the 2nd equation.

-15j - 9a = -57

7j + 9a = 35

Adding the equations...

-8j = -22

j = $2.75

5(2.75) + 3a = 19

13.75 + 3a = 19

3a = 5.25

a = $1.75

Hope this helps!