**Student Instructions**

Are you up for the challenge? The Math Club at Donna's school had a Math Carnival. At her booth, Donna set up three scales with baseballs, tennis balls and soccer balls, as shown in the picture. How much does each kind of ball weigh? Analyze the picture on the slide. Use the , or tool to define variables and write an algebraic system of equations to represent the picture. Solve the system algebraically. Show your calculations using the , and/or tool. Or, upload a photo of you work on paper . Use the tool to record the correct weights of each ball. When you have completed the challenge, click on the green check to submit your activity.

b + t + s = 19 2t + 2s = 28 2b + s = 22 There are several different approaches, but most students recognize that by dividing the second equation in half we know t + s = 14. Thus, we can rewrite the first equation as b + 14 = 19 (substituting 14 in for t + s). Therefore, a baseball weighs 5 oz., a soccer ball weighs 12 oz. and a tennis ball weighs 2 oz.