To determine which equation can be used to find \( d \), the number of days it will take for Cory's plant to reach 15.5 cm, we can start by expressing the height of the plant as a function of days.
Initially, the plant is 5 cm tall, and it grows at a rate of 1.5 cm per day. Therefore, after \( d \) days, the height of the plant will be:
\[ \text{Height} = 5 + 1.5d \]
We want to find out when this height equals 15.5 cm:
\[ 5 + 1.5d = 15.5 \]
Now, let's check the responses to see which matches this equation:
- A: \( 5 - 1.5d = 15.5 \) (incorrect format)
- B: \( 5d + 1.5 = 15.5 \) (incorrect format)
- C: \( 5 + 1.5d = 15.5 \) (correct!)
- D: \( 5d - 1.5 = 15.5 \) (incorrect format)
The correct equation that can be used to find \( d \) is:
C: \( 5 + 1.5d = 15.5 \)