Set the composite results function.

Evaluate f(g(x)) by substituting the value of g into f.

Simplify each term.
Apply the distributive property.
Multiply 4 by 2.
Multiply 2 by 3.
Subtract 5 from 6.

Answer:
the correct answer is option A. Length
In this question, the speed of the dolphin is already given, but the unit is different. The speed of the dolphin is given as 40 miles per hour and it has to be converted to feet per hour.
We already know that 1 mile = 5280 feet
Then
40 mile = 5280 * 40 feet
= 211200 feet
So the speed in feet per hour will be 211200 feet per hour. I hope the procedure is clear enough for you to understand. You can always use this method for solving similar problems without requiring any help from outside.
Step 1
Collinear points are a set of three or more points that exist on the same straight line. Collinear points may exist on different planes but not on different lines.
Step 2
Graph the points; (-5,2),(0,6),(6,4)
Step 3
Conclude based on step 2
Since the points are not a straight line, we can conclude that the 3 points are not collinear.