Question

A contractor uses the expression
7(x +3) to find the length in feet of chain that he needs for a certain project.

The contractor needs four chains that are the this length what is the total length of all of the chains

Part b the contractor needs another chain that is 50% longer than the first chain write an expression he can use to find the length of this chain explain how you know your expression is correct

Answer 1

The length of the chain is 7(x+3).

Four times this would be 4(7(x+3)) = 28(x+3) = 28x+84
(either answer is good depending on whether you should distribute or not)

50% longer than this would be 1.5(7(x+3)) = 10.5(x+3) = 10.5x+31.5
(to be 50% longer, we multiply by 1.5...1 whole + 1 half)
We could write this in other different ways, such as 21(x+3)/2 = (21x+63)/2...