Guillen floors advertise the same type of carpet at a cost of 10% less per square foot then Harlem Hardware determine the cost of 700 square feet of carpet if it is bought from guillen floors

This question is incomplete. Harlem sells 500 square feet at $750

cost per square foot = 500/750 = $1.50

10% of $1.50 is 0.15

cost per square foot - 10% discount = $1.50 - $0.15 = $1.35

Therefore, Guillens cost for 700 square foot is $1.35 * 700 = $945