Answer:
y=x+3
Step-by-step explanation:
The equation "y=x+3" cannot be written in the form y=kx because the form doesn't use addition as a basic operation. Let's try verifying the choices:
y=x is possible if the value of k is 1, provided that both y and x are of the same value.
y/2=x is possible because y=2x, provided that 2 is the value of k.
y=-1/10x is possible because -1/10 is the value of k. This is just the same with y=kx.