The equation that represents the fraction of cake remaining is x - 2/3x.
The diagram is attached
What fraction of cake is remaining?
Let
The total cake = x
Moe = 1/12 of x
= 1/12x
Larry = 2/12 of x
= 2/12x
Curly = 5/12 of x
= 5/12x
Total cake eaten by the children = 1/12x + 2/12x + 5/12x
= 8/12x
= 2/3x
The fraction of cake remaining = The total cake - Total cake eaten by the children
= x - 2/3x
= (3-2)x/ 3
= 1/3x
Hence, 1/3 is the fraction of cake remaining.