Multiplying a vector by a scalar means to multiply each coordinate of the vector by said scalar.
So, we must multiply both entries by 7:

6:5
basically 12/10
which then reduces. hope this helps :)
Yes because the gap is one less than the bigger of the two integers, plus you are adding a little bit more to the bigger integer so the sum will always be bigger than the difference.
8-x because you are seeing how tall it grew this week