Suppose B is the midpoint of AC. AB = 5x and BC = 3x + 4. Find AB.

5x=3x+4

Subtract 3x from both sides.
Divide both sides by 2.

To find the length of AB, we can use the fact that B is the midpoint of AC. This means that the length of AB is equal to the length of BC.

We are given that AB = 5x and BC = 3x + 4. Since B is the midpoint of AC, AB must be equal to BC. So, we can set up the equation:

5x = 3x + 4

To solve for x, we will isolate the variable by subtracting 3x from both sides of the equation:

5x - 3x = 4

Simplifying the equation:

2x = 4

Next, we need to solve for x by dividing both sides of the equation by 2:

2x / 2 = 4 / 2

Simplifying:

x = 2

Now that we have found the value of x, we can substitute it back into the equation for AB:

AB = 5x
AB = 5(2)
AB = 10

Therefore, the length of AB is 10.