Answer: Cost of a side dish = $ 7
Cost of a roll = $1
Cost of prime rib = $21
Step-by-step explanation:
Let x = cost of a side dish , y= cost of a roll
Then, cost of a prime rib = 3x
Jackie's meal : prime rib, 2 side dishes, and a roll, it came to $36
i.e. 3x+2x +y = 36
⇒ 5x+y=36 (i)
Ted's meal : prime rib, 3 side dishes, and 2 rolls, it came to $44.
i.e. 3x+3x +2y = 44
⇒6x+2y=44
⇒ 3x+ y= 22 (ii) [divide both sides by 2]
Subtract (ii) from (i), we get
2x= 14
⇒ x=7 [divide both sides by 2]
Put x=7 in (ii), 3(7)+y=22
⇒ 21+y=22
⇒ y =22-21
⇒ y= 1
So, cost of a side dish = $ 7
cost of a roll = $1
cost of prime rib = 3x $7 = $21
