point B lies between points A and C on AC let X represent the length of segment a b in inches

Using the Segment Addition Postulate, it is found that:
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From the Segment Addition Postulate: Segment AC is divided by segment AB and segment BC, thus:
[tex]AC = AB + BC[/tex]
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We have that:
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Solving for x.
[tex]AC = AB + BC[/tex]
[tex]20 = x + 3x[/tex]
[tex]4x = 20[/tex]
[tex]x = \frac{20}{4} = 5[/tex]
The length of x is of 5 inches.
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A similar problem is given at https://brainly.com/question/17015370