Three trains - one eastbound, one westbound, and one northbound - leave a city at the same time.
The speed of the northbound train is 20 miles per hour greater than the speed of the eastbound train.
After 9 hours, the distance between the westbound train and the eastbound train is 990 miles.

mental cunning

explanation:

he is often referred to as a man of twists and turns

2425

step-by-step explanation:

answer: c

substitute in the values.

for a:

f(0) = 0 + 9

f(0) = 9

a is a solution.

for b:

f(7) = 14 + 9

f(7) = 23

b is a solution.

for c:

f (3) = 6 + 9

f(3) = 15

c is not a solution. it's supposed to be 14.

for d:

f(2) = 4 + 9

f(2)= 13

d is a solution.