Question

When Edna's phone is fully charged, it can operate for up to 18 hours before running out of battery. It has been 6 hours since Edna's phone was fully charged.
Let x represent how many more hours Edna's phone can operate without running out of battery. Which inequality describes the problem?
Solve the inequality. Then, complete the sentence to describe the solution.
Edna's phone can operate for up to more hours without running out of battery.

Answer 1

Given that Edna's phone can operate for a total of 18 hours when fully charged and it has already been 6 hours since it was fully charged, we can represent the remaining operating time with the variable \( x \).

The operation time left \( x \) can be expressed as:
\[
x + 6 \leq 18
\]

This inequality states that the total time the phone has operated (which is the sum of the time already spent and the time left) should not exceed the total operating time when fully charged.

Now, let's solve the inequality:

1. Start with the original inequality:
\[
x + 6 \leq 18
\]

2. Subtract 6 from both sides:
\[
x \leq 18 - 6
\]
\[
x \leq 12
\]

This indicates that the phone can operate up to 12 more hours before running out of battery.

Completing the sentence based on the solution:
Edna's phone can operate for up to **12** more hours without running out of battery.