Stephen and Rocco each have apps on their phones.
• The number of apps on Stephen’s phone can be represented by x.
• The number of apps on Rocco’s phone is 4 times the number of apps on Stephen’s phone.
• The total number of apps on both boys’ phones is at least 45.
What is the solution set for x, the number of apps on Stephen’s phone?
Responses
A x ≥ -9x ≥ -9
B x ≤ 9x ≤ 9
C x ≥ 9 x ≥ 9
D x ≤ -9
Let's represent the number of apps on Stephen's phone as x.
According to the second bullet point, the number of apps on Rocco's phone is 4 times the number of apps on Stephen's phone. So, the number of apps on Rocco's phone is 4x.
The total number of apps on both boys' phones is at least 45.
Therefore, we can write the equation: x + 4x ≥ 45.
Simplifying this, we get 5x ≥ 45.
Dividing both sides of the equation by 5, we get x ≥ 9.
So, the solution set for x, the number of apps on Stephen's phone, is x ≥ 9.
Therefore, the correct answer is C) x ≥ 9.