Given :
Kiara spent $28 on 4 ribbons and 5 balloons.
Sarah spent $28 on 8 ribbons and 3 balloons.
To Find :
The cost of each ribbon and each balloon.
Solution :
Let, cost of each ribbon is x and balloon is y.
For situation 1 :
4x + 5y = 28 ...1)
For situation 2 :
8x + 3y = 28 ...2)
Multiplying equation 1) by 2 and subtracting equation 2) by it :
2( 4x + 5y ) - ( 8x + 3y ) = 2 × 28 - 28
10y - 3y = 28
y = 4
Putting value of y in equation 1) , we get :
Therefore, the cost of each ribbon and each balloon is $2 and $4 respectively.