Are these two lines parallel, perpendicular, or neither? Explain. $9x+3y=8$ , $3x+9y=8$

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Answer 1 · 2015-11-24T20:31:18

The given lines are neither parallel nor perpendicular.

To check if two lines are parallel or perpendicular it is good to change the equations to form $y=ax+b$

The first line is:

$9x+3y=8$

$3y=-9x+8$

$y=-3x+8/3$

The second line is:

$3x+9y=8$

$9y=-3x+8$

$y=-1/3x+8/9$

From those equations we can see that those lines are **neither parallel nor perpendicular **

They would be parallel if the coefficients of $x$ were equal.

They would be perpendicular if the coefficients of $x$ were inverse and opposite numbers (for example $3$ and $(-1/3)$ or $(-2)$ and $1/2$ )

Are these two lines parallel, perpendicular, or neither? Explain. 9x+3y=89x+3y=8, 3x+9y=83x+9y=8