Which two lines are parallel?

3x + y = -2 ***

2y – 6x = 4

2y = -6x – 8 **

how do i check if they're

Step-by-step explanation:

When the equations are written in the same form, the ratio of x coefficient to y coefficient is the same for parallel lines.

These equations in the same form are ...

The first and last of these equations have a ratio of x-coefficient to y-coefficient of ...

  (x-coefficient)/(y-coefficient) = 3/1 = 6/2

so the lines are parallel.

The second equation has a ratio that is the opposite of this.

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Alternate approach

You can put each equation into slope-intercept form (solve for y). The x-coefficient is then the slope of the line. Parallel lines** have equal slopes.

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I find a graphing calculator to be a big help for many problems involving equations and their characteristics.