Answer:
Explanation:
Three of you is 3 Sarahs. 3 times a number is 3n, or 3-whatever letter you pick. Subtract 19 from that...
3n - 19
If it confuses you, pick an actual number to use. 19 subtracted from 3 times 6.
3(6) - 19
Instead of solving and getting 1, just replace the 6 with a letter. Most people like to use x, but I used n since "number" starts with n.
3n - 19