They are not the same thing.
Answer:
Step-by-step explanation:
Fire house Light = 90
30=30-90
Answer: d. He multiplied when he was supposed to divide
Step-by-step explanation:
He just multiplied across when he was supposed to divide (or cross multiply) to find the unit rate :)
This question seems to me to be an exercise in applying the rule for a difference of squares in order to rewrite the difference of two relatively large numbers as the "simpler" product of other integers.