Cassie has 8 red and 12 yellow marbles. her mom doubles her collection. use tyhe distributive property to show how many she has now.

2(8+12)
2(8)+2(12)
that is 16 plus 24 which makes 40

Since she's starting 2 inches in, the total length that we have left to split is 58 in. next, we divide the total length, 58, by the total number of pieces we are splitting the ribbon into, 5 (2+3=5). once we divide 58 by 5, we get 11.6. multiply this number by the ratio we are splitting the ribbon into, so we do 2(11.6) and 3(11.6). multiplying 2 and 11.6 gives us 23.2 and multiplying 3 and 11.6 gives us 34.8. we can double check our answer by adding the 2 numbers together and since we do get the original length (58), we know we did the problem correctly.