Question

A restaurant charged one customer $28.20 for 3 small dishes and 5 large dishes and charged another customer $23.30 for 4 small dishes and 3 large dishes. Use x for small dishes and y for large dishes. What will 2 small dishes and 4 large dishes cost?

Answer 1

Answer: $21.40

Explanation:

The information in the question can be represented into an equation as:

3x + 5y = 28.20 ........ i

4x + 3y = 23.30 ......... ii

Multiply equation i by 4

Multiply equation ii by 3

12x + 20y = 112.80 ..... iii

12x + 9y = 69.90 ....... iv

Subtract iv from iii

11y = 42.90

y = 42.90/11 = $3.9

Large dish cost $3.90

Since 3x + 5y = 28.20

3x + 5(3.90) = 28.20

3x + 19.50 = 28.20

3x = 28.20 - 19.50

3x = 8.70

x = 8.70 / 3 = $2.90

Small dish cost $2.90

The cost of 2 small dishes and 4 large dishes cost will be:

= 2($2.90) + 4($3.90)

= $5.80 + $15.60

= $21.40