Diego buys a photo album during the sale. If Diego pays $4, what was the original price? It it 50% off the original price.

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?

3x + 4y = 5 x- 3y = -7 solve by substitution

Four quarts of a latex enamel paint will cover about 200 square feet of wall surface. how many quarts are needed to cover 98 square feet of kitchen wall and 52 square feet of bathroom wall