Firstly, get it into y=mx+b form
Subtract 10x
2y=-10x+4
Divide by 2
y=-5x+2
Change y to f(x) to make it into function notation
f(x)=-5x+2
Let's assume that the function's name is "y." We need to solve 10x+2y=4 for y:
2y = 4 - 10x, or y = 2 - 5x.
