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

Question

asked Feb 24, 2018 55.3k views

2 Answers

Nickofthyme · Answer 1 · 2018-03-01T07:11:49+0000

Answer:

y=3x+1

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:

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