Question: You are tasked with designing a linear function to model the cost C(x) of a subscription plan that charges a fixed initial fee plus a monthly charge. The following points represent the cost at different months: At month 1, the cost is $25; At month 3, the cost is $35; At month 6, the cost is $50. Which equation best models the situation?
A) C(x)=5x+20
B) C(x)=10x+15
C) C(x)=1/2x+5
D) C(x)=7.5x+17.5
Correct answer: A
Grade: 8 | Topic: Functions | Difficulty: Medium | Standard: 8. F. B. 5