How do you simplify 7a22a2?

1 Answer
Nov 3, 2015

7a22a2=5a2

Explanation:

Suppose you have square sheets of material; each sheet is identical to every other sheet and each sheet has dots arranged in a rectangular grid of a rows and a columns. There are a×a=a2 dots on each sheet of material.

Suppose you start the day with 7 such sheets of material; you start with 7×a2 or more simply 7a2 dots.

If during the day you lose 2 of those sheets of material, you will have lost 2×a2 or 2a2 dots.

During the day, 7 sheets minus 2 sheets becomes 5 sheets
XXX7 sheets2 sheets=5 sheets
and 7×a2 dots minus 2×a2 dots becomes 5×a2 dots
XXX7a22a2=5a2