Explanation:
a parallel line has the same slope. that is the actual meaning of "parallel".
so we need to find the slope of line t to get our answer.
remember, the slope is the ratio " y coordinate change / x coordinate change" when going from one point on the line to another.
so, here we have 2 points (9, 10) and (3, 3).
going from the first to the second we see
x changes by -6 (from 9 to 3).
y changes by -7 (from 10 to 3).
the slope is then -7/-6 = 7/6.
and therefore, the slope of u is also 7/6.