Sara makes $255 for working 15 hours and makes $680 for working 40 hours. What is the constant of proportionality (unit rate) of Sara's rate of pay per hour? A. 15
B. 2.6 repeating
C. 17
D. 12

15

Step-by-step explanation:

As defined in the lesson on Unit Rate and Proportionality, the unit rate is the rate of change in a relationship where the rate is per 1. The rate of change is the ratio between the x and y values in a table. Another term for the rate of change for proportional relationships is the constant of proportionality.

C.17

Step-by-step explanation:

255/15 = 17

680/40 = 17

15*17 = 255

40*17 = 680

2(2x + 3) = -4 + 2(2x + 5)

4x + 6 = -4 + 4x + 10

4x + 6 = 4x + 6

4x - 6 + 6 = 4x - 6 + 6

4x = 4x

x = x

unlimited solutions.