Lisa uses 2 pieces of copper wire, each 9 feet long, for each robot she builds. If she started with a 500-yard roll
of copper wire, which of the following represents the
number of yards of wire left on the roll after 'Lisa built r
robots? (3 feet = 1 yard)

yards of wire left on the roll = 500 - r(3)

Step-by-step explanation:

9 feet = 3 yards we need to find how much wire is left on the roll after she builds a certain amount of robots. she uses 9 feet or 3 yards per robot so we have to multiply the amount of robots (r) by 3 yards and subtract that from 500 yards or the total amount of wire she has and that gives us the total amount of wire she has left. Hope this helps.

correct

step-by-step explanation:

it's