Points a b c lie on one straight line a b is equal to 15 centimeters segment ac is 4 times larger than segment BC find segment ac.

By condition, it is specified that points a, b, c lie on one straight line, a b is equal to 15 cm, segment ac is 4 times larger than segment bc. Because the segment bc is not specified by the condition of the problem, we denote its value through the variable x cm, then the segment ac will be equal to 4x cm.Let’s make an equation, for this it is necessary to find the difference between the segments ac and bc, as a result we get the segment ab:
ab = ac – bc;
4x – x = 15;
3x = 15;
x = 15: 3;
x = 5 (cm) – the length of the segment bc;
Let’s find the length of the segment ac:
4x = 4 * 5 = 20 (cm) – the length of the segment ac.
Answer: the length of the segment ac is 20 cm.