You order two tacos and a salad. The salad costs $2.50. You pay 8% sales tax and leave a $3 tip. You pay a total of $13.80. How much does one taco cost? Let t represent the cost of one taco.

Let T = cost of a taco

Let S = cost of a salad

(2 tacos + 1 salad) + (8 % of 2 tacos and 1 salad) + 3 = 13.80

2T + S +.08 (2T + S) + 3 = 13.80

2T + 2.5 +.08 (2T + 2.5) + 3 = 13.80

2T + 2.5 +.16T +.20 + 3 = 13.80

2.16T + 5.7 = 13.80

2.16T = 8.10

T = 8.10/2.16 = $3.75

Check: 2T + S +.08 (2T + S) + 3 = 13.80

2 (3.75) + 2.50 +.08 (2 (3.75) + 2.5) + 3 = 13.80

7.5 + 2.5 +.08 (10) + 3 = 13.8

13.80 = 13.80

Answer checks as correct