Question

Which lines are perpendicular to 5x + 4y = 8?

Choose all answers that are correct.

–5x + 4y = –5
5y = –4x – 15
5y = 4x + 5
–4x + 5y = 10

Answer 1

-5x+4y=-5 and -4x + 5y=10 is perpendicular

Answer 2

How? Can you please explain? :):):)

Answer 3

Perpendicular lines have the same slope.

Answer 4

Change 5x + 4y = 8 into the form of y = mx + b to find its slope.

5x + 4y = 8

Subtract 5x to both sides:

4y = -5x + 8

Divide 4 to all terms:

y = -5/4x + 2

So the slope of 5x + 4y = 8 is -5/4.

Answer 5

perpendicular lines have negative reciprocal slopes. All that means is if you have a slope of 4/5....to find perpendicular, you " flip " the slope and change the sign...so the negative reciprocal of 4/5 is - 5/4.

That being said...you will need to put the original equation in y = mx + b form, where m is your slope.
5x + 4y = 8
4y = -5x + 8
y = -5/4x + 2
but we need perpendicular...so we need the slope of 4/5...see how I flipped the slope and changed the sign.

Now you would just have to go through all the answer choices, putting them in y = mx + b form....and the ones that have a slpe of 4/5 are your perpendicular lines.

any questions ? Not too hard...just time consuming

Answer 6

Ohh, it said Perpendicular..xD

Answer 7

Perpendicular lines have OPPOSITE slope.

Answer 8

these aren't hard...just a little time consuming

Answer 9

5y = 4x + 5 --> y = 4/5x + 1

This is perpendicular to the original equation, 5x + 4y = 8.