One pair of dress socks costs 5.25
Work Step by Step
Let X represent the cost of a pair of athletic socks. Dress socks cost 2.50 a pair more than athletic socks. Thus, we obtain that if athletic socks cost X, dress socks cost X + 2.50. Randall purchased one pair of dress socks and six pairs of athletic socks for 21.75. One pair of dress socks means X + 2.50 And six pairs of athletic socks means + 6X Thus, we obtain: X + 2.50 + 6X = 21.75 7X + 2.50 = 21.75 Subtract 2.50 from both sides: 7X = 19.25 Divide both sides by 7: X = 2.75 Since one pair of dress socks costs X + 2.50, and X = 2.75, one pair of dress socks costs 5.25.