Question

my teacher asked this question but im not sure what he means, The longest interstate highway in the Us is I-90, the second longest is I-80, which is 178.5 miles shorter than I-90. if the length of I-80 is m miles, express the length of I-90 as an algebraic expression in m......... but isn't he saying they both are expressed as m?

Answer 1

No, this means calling the length of I-80 m, and we want the length of I-90 in terms of I-90. Since the I-90 is 178.5 miles longer, then the length of I-80, or m, plus that 178.5, should give you the length of I-90.
This would be written as m + 178.5 = length of I-90