Answer:
+5 is the slope
Step-by-step explanation:
In this problem, you're looking for the value of t, so that f(t) = 48. That means if you put t into 5t-7, you'll get 48. To do this set up and solve an equation for t by setting 48 equal to 5t-7:

Isolate the variable by adding 7 to both sides.

Divide by 5 on both sides to find t.

The answer is 11.
Translation right down c=
Distance to travel = 20 m.
Let us determine the time, t, that each participant took to complete 20 m.
Barbara:
Average speed = (3 m)/(2 s) = 1.5 m/s
t = 20/1.5 = 13.3 s
Mark:
t = 5 s
Carlos:
y = x + 1
where
y = 20 m
x = time, t
Therefore
t =x = y - 1 = 20 - 1 = 19 s
Summary:
Barbara: 13.3 s
Mark: 5 s
Carlos: 19 s
Answer:
The winner is Mark