Question

Which of the following is an equation of a line parallel to 2x-y=-1?

Answer 1

Although you didn't provide a list of options to choose from, I hope my explanation will help you  work this out with ease. :)

This equation is in a form known as "standard form." ax+by=c Standard form is commonly used, however for comparing slopes, there is a more efficient equation to use.

Point-slope form (y=mx+b) allows lines' slopes (y) and y-intercepts (b) to be quickly compared and contrasted. Let's put the equation into this form.

2x-y=-1

-2x      -2x

-y = -1 - 2x

*-1      *-1

y= 1 + 2x

Switch pieces around

y= 2x + 1

The slope is 2, the y intercept is 1.

Any line that rises 2 units up for every one unit right and that crosses over the vertical axis at any point other than 1 is your answer.