red has some colored kitchen floor tiles and wants to choose a pattern
sing them to make a border around white tiles. He generates patterns by
tarting with a row of four white tiles. He surrounds these four tiles with a
order of colored tiles (Border 1). The design continues as shown below:
Border 1
Border 3
red writes the expression 4(b-1)+10 for the number of tiles in each border, where
is the border number, b21. Explain why Fred's expression is correct.
Border 2