Okay. The phone is free, so that does not cost any money.
The company charges you £10 each month and 5p for every text.
1) Let's see. We know it says "In May," which is just one month. Therefore, you will pay £10 for the month.
However, we are not done! You also send 11 texts and each text is 5p, so to find the cost we do \(5p\times11=55p\).
\(55+10=65\) so the total cost would be 65 pounds.
The answer would be £65.
2) We do the same strategy. Again, we only need to pay for one month as it says "In June." Therefore, you will pay £10 for the month.
Again, we are not done! This time, you text a whopping 80 texts, but we still simply do \(5p\times80=160p\).
\(10+160=170\)so the total cost would be 170 pounds.
The answer would be £170.
3) This is really simple since you don't send any texts, you get only the monthly bill, £10.
The answer would be £10.
4) We always need to pay £10 per month, so we know the "C" part of the equation is actually \(10C\) .
For the texts, you always pay £5 per text, so the text part of the equation is simply \(5T\).
Therefore the equation would be \(10C+5T\)
You are very welcome!
:P