Answer:
Similar to SIN = 0
We show the partial 4y + 10 = 3x
just the same as we can say 3x-10 =4y
We could say (f)y= 1 and (f)x= -1 the actual function changes x to 10x and y to 10x its value and this can be expressed with a curly d that acts the same.
The notation is just replaced with f(x) and f(y)
Explanation: