The total cost of 3 jackets and 3 blazers was $171. Tina bought 5 such jackets, 3 such blazers and a cardigan for $263. If the total cost of a dress and a jacket was $59, find the difference in cost between the jacket and the dress.
Let 1 J be 1 jacket.
Let 1 B be 1 blazer.
Let 1 D be 1 dress.

3 J + 3 B = 171 --- (1)

1 J + 1 B = 171 ÷ 3
1 J + 1 B = 57 --- (2)

1 J + 1 D = 59 --- (3)

5 J + 3 B + 1 D = 263 --- (4)

(4) - (1)
(5 J + 3 B + 1 D) - (3 J + 3 B) = 263 - 171 
5 J - 3 J + 3 B - 3 B + 1 D = 92

2 J + 1 D = 92 --- (5)

(5) - (3)
(2 J + 1 D) - (1 J + 1 D) = 92 - 59
2 J - 1 J + 1 D - 1 D = 33
2 J - 1 J = 33

1 J = 33

From (3)
1 J + 1 D = 59
33 + 1 D = 59

1 D = 59 - 33 = 26

Difference in the cost between the jacket and the dress
= 1 J - 1 D
= 33 - 26
= $7

Answer(s): $7