<PRE><B>Question 310558</B>
cheap ball be $x
expensive ball be $y

Shanon - cost equation

10x+7y= 31.75
Piper - cost equation
8x+5y= 23.75

8(10x+7y)-10(8x+5y)= 8*31.75 - 10*23.75

80x+56y-80x-50y=252-237.5
6y=14.5
y=2.42
Plug the value of in one equation

10x+7*2.42 =31.75
10x= 31.75-16.94
10x= 14.81
x=1.48
CHECK

10*1.48+7*2.42=31.74


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