Answer:
The number of:
300- yen cakes = x = 4
350 - yen cakes = y = 6
Explanation:
Let the number of:
300- yen cakes = x
350 - yen cakes = y
You buy some 300-yen pieces of cake and some 350 yen pieces of cake. If you buy 10 pieces of cake and pay 3300 yen, how many of each kind did you buy?
Hence, our system of equations derived from the question is:
x + y= 10 ..... Equation 1
x = 10 - y
300x + 350y = 3300 yen... Equation 2
Substitute 10 - y for x in Equation 2
Hence:
300(10 - y) + 350y = 3300
3000 - 300y + 350y = 3300
- 300y + 350y = 3300 - 3000
50y = 300
y = 300/50
y = 6
x = 10 - y
Substitute 6 for y
x = 10 - 6
x = 4
Therefore, the number of:
300- yen cakes = x = 4
350 - yen cakes = y = 6