Make up expressions for the length of an open polyline ABCD if AB = y m, BC

Make up expressions for the length of an open polyline ABCD if AB = y m, BC is 7.35 cm less than AB, and CD is 5.12 dm more than AB and simplify it.

Let’s solve this task by actions with explanations:
1) AB – 7.35 = y -7.35 centimeters – the length of the BC link of the broken ABCD, since BC is 7.35 centimeters less than AB;
2) AB + 5.12 = y + 5.12 centimeters – the length of the link BD of the broken line ABCD, since CD is 5.12 centimeters less than AB;
3) y + y -7.35 + y + 5.12 = y + y + y – 2.23 centimeters – the length of the broken line ABCD.
Answer: y + y + y – 2.23 centimeters.