Answer:
X=-1
Step-by-step explanation:
0=2x+2
subtract 2 out
-2 = 2x
divide 2 on both sides x = -1
Answer: Your answer is the third one, a function assigns to each input exactly one output.
If you have a true function, there will only be one output for each input, if you had more than one, it isn't a function.
Proportional equations are the equations that have the graph which pass through (0,0).
y = -9x is proportional.
y=x is proportional
y=1/2x is proportional
That's it. Only these three equations have (0,0) intercept.