Question

Which Equation best represents the line graphed above? Y=-3x-1 Y=-3x+1 Y=3x+1 Y=3x-1

Answer 1

C. y=3x+1 is the answer.

Answer 2

Answer:

$y=3x+1$

Step-by-step explanation:

The line has positive slope, therefore the variable in the equation must be positive ($y=-3x+1$ and $y=-3x-1$ must be discarded)

Now, in the graph we can see that the line passes over the following points:

$(0,1) \rightarrow x=0, y=1\\(1,4) \rightarrow x=1, y=4$

With the point $(0,1)$, we can discard $y=3x-1$ because:

in the equation  $y=3x-1$, we have: $x=0 \rightarrow y=3(0)-1=0-1=-1\rightarrow y=-1$

The line doesn't pass over the point $(0,-1)$

Therefore, the equation is $y=3x+1$.

We can verify the answer with the points $(0,1)$ and $(1,4)$, replacing values in the equation:

$(0,1):\\x=0\rightarrow y=3(0)+1=0+1=1\rightarrow y=1\\\\(1,4):\\x=1\rightarrow y=3(1)+1=3+1=4\rightarrow y=4$