Question 76067

Let x=number of of 11 in balls
Then 80-x=number of 12 in balls

Total cost of 11 in balls plus total cost of 12 in balls equals $210

So, our equation to solve is:

2.25x+2.75(80-x)=210  get rid of parens

2.25x+220-2.75x=210  subtract 220 from both sides

2.25x+220-220-2.75x=210-220  collect like terms

-0.50x=-10  divide both sides by -0.50
x=20---------------------------------------------number of 11 in balls

80-x=80-20=60---------------------------------------number of 12 in balls


CK

2.25(20)+2.75(60)=210
45+165=210
210=210


Hope this helps---ptaylor