Answer: See explanation
Explanation:
Your question isn't complete and I couldn't get the exact question online but let's reframe it and solve it.
The restaurant manager wants to find how much they are spending for pies and cakes. Last week they payed 204$ for 12 pies and 8 cakes. This week, they paid $129 for 5 pies and 7 cakes.
Let's say the cost of pies is x
Let's say the cost of cake is y.
We'll then use the information given to make an equation which will be:
Last week they payed 204$ for 12 pies and 8 cakes. This will be:
12x + 8y = 204........ i
This week, they paid $129 or 5 pies and 7 cakes. This will be:
5x + 7y = 129 ........... ii
Therefore,
12x + 8y = 204........ i
5x + 7y = 129 .......... ii
Multiply equation i by 5
Multiply equation ii by 12
60x + 40y = 1020 ....... iii
60x + 84y = 1548 ........ iv
Subtract iii from iv.
44y = 528
y = 528/44
y = 12
The cost of cake is $12.
From equation i,
12x + 8y = 204
12x + 8(12) = 204
12x + 96 = 204
12x = 204 - 96
12x = 108
x = 108/12
x = 9
The cost of pies is $9.