Question

Can any moderators help me?

Answer 1

Find the slope of a line perpendicular to each given line.

2x+5y=-15

Y=-3/2x+1

Answer 2

@miracrown are you good at math?

Answer 3

@pooja195

Answer 4

mods arent alwats good at math they are here to make sure we are behaving

Answer 5

always*

Answer 6

In general, when you have a line in a form \(\color{black}{y=mx+b}\),
then the slope of a(ny) line perpendicular to the line above is \(\color{black}{-1/m}\).

Answer 7

Actually, perhaps as a coincidence, but most of them are good at math:)

Answer 8

Oh okay. Umm how do I go on

Answer 9

Well, try to re-write each line in the same format (like \(\color{black}{y=mx+b}\)).

Answer 10

How do I do that. Sorry I'm not good at math

Answer 11

5y= -2x+15

y= -2x/5+15

y= -2x/5+3?

Answer 12

Example: \(\color{black}{4y+6x=9}\)

First we re-write using algebraic manipulations.
\(\color{black}{4y+6x\color{red}{-6x}=\color{red}{-6x}+9}\)
\(\color{black}{4y=-6x+9}\)
\(\color{black}{\color{red}{(}4y\color{red}{)\div 4}=\color{red}{(}-6x+9\color{red}{)\div 4}}\)
\(\color{black}{y=-\frac{3}{2}x+\frac{9}{4}}\)

So, the slope is -3/2.
Thus, a perpendicular line will have slope of 1 divided by that.
In other words, \(\color{black}{\frac{1}{-\frac{3}{2}}=-1\div \frac{3}{2}=-1\times \frac{2}{3}=\frac{-2}{3}}\).

Answer 13

Is my answer above right?

Answer 14

You rearranged it correctly. In other words, you solved for y correctly.

Answer 15

Okay. What do I do next?

Answer 16

For any line \(y=mx+b\), the slope is \(m\).
So in your case what is the slope?

Answer 17

I don't know

Answer 18

y= -2x/5+3 is your equation. (You solved for y correctly, good job on that!)

Answer 19

Given what I said just now (which is a rule for any line), what is the slope of your line?

Answer 20

-2/5?

Answer 21

@solomonZelman

Answer 22

yes, correct.

Answer 23

So, since your slope is -2/5, the slope of a perpendicular line would be 1 divided by that.

Answer 24

In other words, your slope is:
\(\large \bf \frac{~~~-1~~~}{\frac{-2}{5}}=-1 \div \frac{-2}{5}=\)

Answer 25

It would still be the same answer right?

Answer 26

all that remains to you is to simply.

Answer 27

The same as what?
You haven't posted any answer.

Answer 28

You posted the rearrangement where you solved your equation for y, which is correct, and identified the slope.

Answer 29

It would still be -2/5? If you divided it by 1

Answer 30

no, it wouldn't

Answer 31

@BlueMoon1
Actually both mods are good at math, but @sarahhanish 's comments remain valid.

Answer 32

cool dont add me on this no more :0

Answer 33

Can you finish dividing?

\(\large \bf \frac{~~~-1~~~}{\frac{-2}{5}}=-1 \div \frac{-2}{5}=\)


I will give you a kicker.
The rule is (if \(a\) and \(b\) are both not \(0\))
\(\large \bf x\div \frac{a}{b}=x\times \frac{b}{a}\)

Answer 34

So no solution?

Answer 35

Oh my goodness I don't know.

Answer 36

Proceeding with the rule I just gave above you have:
\(\large -1 \div \frac{-2}{5}=-1 \times \frac{5}{-2}\)

Answer 37

Can you go from there?

Answer 38

That's 5/2

Answer 39

Yup, exactly!

Answer 40

So that's the answer?

Answer 41

Yes, that is the answer.

Answer 42

(The slope of any line which is perpendicular to the line expressed in the question.)

Answer 43

Thanks! I also need help on the other one. If you could do that you would be a lifesaver

Answer 44

If I have time ... I am bouncing here and there right now (kinda).
Will see.

Answer 45

I am pretty sure there are many people who know math better than me, and are also better at explaining it. (Again, will see....) yw

Answer 46

Thanks. I have this whole worksheet that I'm confused on so it really helps thank you