Question

Which equation represents a line which is parallel to the line x-3y=15?

Answer 1

Explanation:

Two lines that are parallel have the same slope. If we make
`x - 3y = 15` in to slope-intercept form it'll be like this:

`x - 3y = 15 \\ -3y = 15 - x \\ y = (15 - x)/(-3) \\ y = (1)/(3)x - 5`

Now we know
`y = (1)/(3)x - 5\\` as its slope-intercept form we can see the slope is
`\frac{1} {3}\\`.

`y = (1)/(3)x + 4\\` has the same slope as
`y = (1)/(3)x - 5\\` so they are both parallel.

Answer:

`y = (1)/(3)x + 4\\`