Question

Which linear function has a y-intercept of -5?

Answer 1

Answer: Upper right corner (northeast corner)

x-3y = 15

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Explanation:

The y intercept always occurs when x = 0.

If we plug x = 0 into 2x+y = -10 (northwest corner), then we solve for y to get...

2x+y = -10

2(0)+y = -10

0+y = -10

y = -10

We see that the y intercept here is -10, but we want -5 instead. So we can rule this out.

In the northeast corner, plugging x = 0 leads to,

x-3y = 15

0-3y = 15

-3y = 15

y = 15/(-3)

y = -5

We get the correct y intercept we're after. So we can stop here.

If you plugged x = 0 into the equation of the southwest corner, you'll get y =  5 which is fairly close but not quite what we want. The southeast corner equation leads to a y intercept of y = 5 as well.

Answer 2

Answer:

x - 3y = 15

Step-by-step explanation:

x - 3y = 15

-3y = -x + 15

y = 1/3x - 5

-5 is the y-intercept.