Answer: D) 20 + 0.10x ≤ 40; She can send 200
Explanation:
Hi, to answer this question we have to analyze the information given part by part:
So, if the number of messages is the variable (x), the money that she spends per month is the sum of the cell phone plan ($20) and the number of text messages sent (x) multiplied by the price of each text ($0.10).
Mathematically speaking:
20 + 0.10x
She does not want to spend more than $40 on her cell phone bill.
So, the expression must be equal or less (≤) than $40:
20 + 0.10x ≤ 40
Solving:
20 + 0.10x ≤ 40
0.10x ≤ 40-20
0.10x ≤ 20
x ≤ 20 / 0.10
x ≤ 200
She can send 200 text messages.
The correct option is D) 20 + 0.10x ≤ 40; she can send 200 text messages.