mr. torres bought 3 chairs on Saturday . he paid d dollars for each chair . mr Torres received $15 dollars in change when he bought the chairs. which expression can be used to find the total amount mr Torres bought for these chairs?

Two customers went to a post office. first customer paid $12 for 14 and 5 envelopes the second paid 24.80 for 10 postcards and 15 envelopes. what is cost of each envelope?

Sanya noticed that the temperature was falling at a steady rate of 1.4 degrees every hour from the time that she first checked her outdoor thermometer. by 6 a.m., the temperature had fallen 21 degrees. which expression can you use to find how many hours earlier she had first checked the thermometer?

What is ha theorem a special case of?