Final answer:
To find x, divide AB by 2, equal it to 4x and solve for x. Then substitute the value of x into the expressions for AM, MB, and AB.
Step-by-step explanation:
To find x, we can set up an equation using the fact that M is the midpoint of AB. Since M is the midpoint, AM = MB. So, we have 4x = (7x + 2) / 2.
To solve for x, we can multiply both sides of the equation by 2 to get rid of the fraction. This gives us 8x = 7x + 2.
Subtracting 7x from both sides, we get x = 2.
Now that we have found x, we can substitute it back into the expressions for AM, MB, and AB. AM = 4(2) = 8, MB = 8, and AB = 7(2) + 2 = 16.