The estimate should be 6.92


as you already know, a direct proportional variation has a constant of variation "k", y = kx, which in this case that'd be the slope, namely 15.
x+7
——— is the simplified version
3
Hi,
The answer would be 300 messages. To explain, there are 60 seconds in a minute so 120 divided by 60 is 2, so that means 2 words per second. So to get the answer for 150 seconds, you multiply 150 by 2 and get 300.
I hope this helps!