Think about the definition of a function. what has to be true? leave a message if you need more help.
X= number of tubs Kasey sold
3x= number tubs sister sold
Add the number sold by Kasey and her sister to equal the total sold (88).
x + 3x= 88
combine like terms
4x= 88
divide both sides by 4
x= 22 number tubs Kasey sold
Number Sold by Sister
3x= 3(22)= 66
CHECK:
x + 3x= 88
22 + 3(22)= 88
22 + 66= 88
88= 88
ANSWER: Kasey sold 22 tubs and her sister sold 66 tubs.
Hope this helps! :)