Explanation:
If Point B lies between points A and C on line segment AC, then the formula is true AB+BC = AC
Given
AB = x inches'
AC = 20 inches
BC = 3x
Substituting the given parameters into the formula AB+BC = AC
x + 3x = 20
4x = 20
Divide both side by 4
4x/4 = 20/4
x = 5
Since x = 5 inches, hence the segment AB id 5 inches.
Given BC = 3x
BC = 3(5)
BC = 15 inches
This means that the space between points A and B is labeled 5 inches while the space between points B and C is labeled 15 inches.