Let's denote the number of minutes of calls as $ x $.

For the first plan:
- Monthly fee: $26
- Additional charge per minute: $0.13

The total cost for the first plan can be expressed as:
$$ \text{Cost}_1 = 26 + 0.13x $$

For the second plan:
- Monthly fee: $15
- Additional charge per minute: $0.17

The total cost for the second plan can be expressed as:
$$ \text{Cost}_2 = 15 + 0.17x $$

We need to find the number of minutes $ x $ for which the costs of the two plans are equal. Therefore, we set the two cost expressions equal to each other:
$$ 26 + 0.13x = 15 + 0.17x $$

Now, we solve for $ x $:

1. Subtract 15 from both sides:
$$ 26 - 15 + 0.13x = 0.17x $$
$$ 11 + 0.13x = 0.17x $$

2. Subtract $ 0.13x $ from both sides:
$$ 11 = 0.17x - 0.13x $$
$$ 11 = 0.04x $$

3. Divide both sides by 0.04:
$$ x = \frac{11}{0.04} $$
$$ x = 275 $$

Therefore, the costs of the two plans will be equal when the number of minutes of calls is 275.

Question

Let's denote the number of minutes of calls as $ x $.

For the first plan:
- Monthly fee: $26
- Additional charge per minute: $0.13

The total cost for the first plan can be expressed as:
$$ \text{Cost}_1 = 26 + 0.13x $$

For the second plan:
- Monthly fee: $15
- Additional charge per minute: $0.17

The total cost for the second plan can be expressed as:
$$ \text{Cost}_2 = 15 + 0.17x $$

We need to find the number of minutes $ x $ for which the costs of the two plans are equal. Therefore, we set the two cost expressions equal to each other:
$$ 26 + 0.13x = 15 + 0.17x $$

Now, we solve for $ x $:

1. Subtract 15 from both sides:
$$ 26 - 15 + 0.13x = 0.17x $$
$$ 11 + 0.13x = 0.17x $$

2. Subtract $ 0.13x $ from both sides:
$$ 11 = 0.17x - 0.13x $$
$$ 11 = 0.04x $$

3. Divide both sides by 0.04:
$$ x = \frac{11}{0.04} $$
$$ x = 275 $$

Therefore, the costs of the two plans will be equal when the number of minutes of calls is 275.

Knowee AI · Accepted Answer