Respuesta :
Answer:
4.50
Step-by-step explanation:
If you use x for burgers and y for fries:
1) 3x+2y=17.50
2) 2x+3y=15
You can then do a simultaneous equation by multiplying the first equation by 1.5 to cancel out the y (fries) to get x (burgers) on its own
1) 4.5x+3y=26.25
2) 2x+3y=15
By subtracting the two equations you get 2.5x=11.25
Then divide 11.25 by 2.5, you get x =4.5 so a burger is 4.50
A burger cost 4.50.
Let the cost of a burger be x.
Let the cost of a fries be y.
Since three burgers and two fries cost 17.50, this will be:
3x + 2y = 17.50 ......... i
Since two burgers and three fries cost 15.00, this will be:
2x + 3y = 15.00 .......... ii
Therefore, both equations will be:
3x + 2y = 17.50 ...... i
2x + 3y = 15.00 ....... ii
Multiply equation i by 2
Multiply equation ii by 3
6x + 4y = 35.00 ....... iii
6x + 9y = 45.00 ....... iv
Subtract equation iii from iv
5y = 10.00
y = 10.00/5
y = 2.00
Therefore, the cost of a frie is 2.00
Since the value of a frie has been gotten, it can be put into any of the equation. Using the equation:
3x + 2y = 17.50
3x + 2(2.00) = 17.50
3x + 4.00 = 17.50
3x = 17.50 - 4.00
3x = 13.50
x = 13.50/3
x = 4.50
Therefore, a burger cost 4.50.
