Question

Use the number line below, where RS = 7y +5, ST = 2y + 7, and RT = 14y - 28.

a. What is the value of y?
b. Find RS, ST, and RT.

Answer 1

a. 8

b. 61, 23, 84

Explanation:

As we can see, point S is between points R and T, therefore:

• RS + ST = RT
• 7y + 5 + 2y + 7 = 14y - 28
• 9y + 12 = 14y - 28
• 14y - 9y = 12 + 28
• 5y = 40
• y = 40/5
• y = 8

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• RS = 7y+5 = 61
• ST = 2y + 7= 23
• RT = 14y - 28 = 84