Question

URGENT - Please Help?!

Write the equation of the line that is parallel to the line 4x - 3y = -12 and passes through the point (-3, 4).

Answer 1

a. y = four thirdsx + 8

b. y = four thirdsx + 3

c. y = -three fourthsx + 8

d. y = -three fourthsx + 3

Answer 2

Sorry for the whole "URGENT" thing - I need this ASAP.

Answer 3

I actually tried to figure this out - I can show you my work if you'd like.

Answer 4

Your answer is a

The gradient is 4/3, you can see that if you write it in the form y=mx + c where m is the gradient.

So y = 4/3 (x) + 12

Plug in -3 you get y to be 8 :)

Answer 5

Oh so you PLUG IN -3?

Answer 6

Yeah it has to pass through that point, and the gradient has to be the same, so it will cross the axis at a different point, you could put -3 or 4 in, you'll get the same answer

Answer 7

Oh okay. Thank you so much. Do you think you could help me on couple more?

Answer 8

Sure

Answer 9

Thanks.

http://orange.flvs.net/webdav/assessment_images/educator_algebra1_v17/03_07_quiz/03_07_14.jpg
Graph with a line going through points negative 2 comma zero and 0 comma negative one.
Select the equation of a line that is perpendicular to the line on the graph and passes through the point (-1, 2).

a. y = 2x + 4
b. y = - 2x + 2
c. y = - 1 over 2 x + 2
d. y = 2x - 1

Now, I know that it cannot be B or C because for this new line to be perpendicular, it had to have a positive slope, right? I think it would be reasonable to say D, am I correct?

Answer 10

You are right, it has to have a positive slope, however I don't think it's D,

If it has to pass through (-1,2) then D, which says y=2x -1 should satisfy these points

So y = 2(-1) + 2 = 0, this does not equal 2

However a,

y = 2x +4

y = 2(-1) + 4
= -2 + 4 = 2

Does satisfy your points.

Do you see how much easier it just to plug in your values and see if they work? :)

Answer 11

So it would be A? Okay! I have another one. (SORRY!)

Write the equation of the line that is perpendicular to the line y = three halvesx + 4 and passes through the point (-6, 3).

y = three halvesx - 1

y = three halvesx + 3

y = -two thirdsx - 1

y = -two thirdsx + 3

Answer 12

It's c

Answer 13

Can you think why? Give me an explanation!

Answer 14

Okay. I think it is because...ooh, no. Well I see that it was three halves and now it is 2/3s. I think you might have plugged in -6.

Answer 15

If it's a line perpendicular to a line you want you always 'flip' the gradient and times by -1. This will make it intersect at 90 degrees :)

So a perpendicular gradient to 3/2 is -2/3!

A perpendicular gradient to 10/7 is -7/10

So it has to be one of the last two, now you can put it in your -6 for x, and see which one of those two gives you y=3, it is the third one :)

Answer 16

Okay. I have one of those questions I want to solve by myself. I am going to show you. Then, I have another one I am stuck on. Here is the one I worked on myself.

Write the equation of the line that is parallel to the line y = 2x + 2 and passes through the point (5, 3).

y = 2x - 7
y = - one halfx - 2
y = 2x - 2
y = - one halfx - 7

"parallel to y = 2x +2"
"passes through the point (5,3)"

y = mx + b, where m = 2, so...
y = 2x + b. I plug in 5 for b.
3 = 2(5) + b
3 = 10 + b
-7 = b

Answer
y = 2x - 7

Answer 17

Yeah, well done :)

Answer 18

:-D

Answer 19

Well, I also have one more question.

Answer 20

Sure :)

Answer 21

http://orange.flvs.net/webdav/assessment_images/educator_algebra1_v17/03_07_quiz/03_07_16.jpg

Select the equation of the line that passes through the point (-2, 3) and is perpendicular to the line on the graph.

y = 0

y = -2

y = 3

y = 3x

Answer 22

That is the last one.

Answer 23

Are you sure it's (-2,3) ?

Answer 24

Yep, I am.

Answer 25

Ok, then the answer is c, y = 3

Answer 26

Can you see how it couldn't be y = 3x, it wouldn't be perpendicular.

And the only one of the other three which gives you a y coordinate of 3 is y=3

Answer 27

Okay. Thans. and I am going to write all the tips you gave me in my notes. ;]

Answer 28

Glad I could help :)