Answer:
They paid $2.85 for each burger and $1.8 for each order of fries
Step-by-step explanation:
It will be solved simultaneously,
let x represent burger and y represent fries
John's order gives the first equation
3x + 2y = 12.15 ........(1)
Emily's order gives the second equation
4x + 3y = 16.80 ..........(2)
multiply equation (1) by 3 and equation (2) by 2 so as to eliminate y
9x + 6y = 36.45 ....... (3)
8x + 6y = 33.6 ........... (4)
subtract equation (4) from (3)
9x - 8x + 6y -6y = 36.45 - 33.6
x = 2.85
substitute x= 2.85 in equation (1)
3(2.85) + 2y = 12. 15
8.55 + 2y = 12.15
2y = 12.15 -8.55
2y = 3.6
y = 1.8
Answer:
Cost of burger = $2.85 and Cost of fries = $ 1.80.
Step-by-step explanation:
Given : john order 3 burgers and 2 fries for $12.15. Emily bought 4 burgers and 3 fries for $16.80.
To find : How much did the pay for each burger and order of fries.
Solution : We have given 3 burgers and 2 fries for $12.15.
Let the cost of 1 burger = x .
Let the cost of 1 Fries = y .
3 x + 2 y = $12.15 ------(1)
4 x + 3 y = $16.80-----(2)
On multiplying (i) by 4 and (ii) by 3 and subtracting the equation .
12x + 8y = $48 .60
(-)12x +(-) 9y = (-)$50 .40
_____________
0 -y = -$ 1.80
y = $ 1.80.
3x + 2(1.80) = $12.15 .
3x + 3.60 = 12.15
3x = 12.15 - 3.60
3x = 8.55
On dividing both sides by 3.
x = $2 .85
Therefore, Cost of burger = $2.85 and Cost of fries = $ 1.80.
