Question

Find an equation of the line having the given slope and containing the given point. m=3/4, (7,-9)

Answer 1

\[y - y_1 = m(x-x_1)\]

Answer 2

point slope formula right but the answer comes out WEIRD here let me do the problem

Answer 3

i got y=3/4-30/4

Answer 4

where'd x go?

Answer 5

oops y=3/4x-30/4

Answer 6

checking..

Answer 7

you should get -57/4 as y-intercept. rest is perfect.

Answer 8

i dont understand why its -57 please explain

Answer 9

y - y1 = m(x-x1)

m=3/4, (7,-9)

y -(-9) = 3/4 ( x - 7)

Answer 10

I have never seen that version of the formula before.

Use: f(x) = mx + b
I think that would be easier.

Answer 11

but this is direct. :P

Answer 12

wait i still don't understand where the -57 came from

Answer 13

please tell me where it came from =(

Answer 14

i did but it came out to be -30/4 i need to understand where and how he got -57 because that's the right answer

Answer 15

\[(y+9)=3/4(x-7)\]
\[(y-9)\times4=3\times(x-7)\]
then multiply and you will get the answer

Answer 16

but thats not part of the formula i am so lost

Answer 17

y -(-9) = 3/4 ( x - 7)
y+9 = 3/4 x - 21/4
y+36/4 = 3/4 x - 21/4
y = 3/4 x - 21/4 -36/4
y = 3/4 x - 57/4

Answer 18

Do you see it now?

Answer 19

can you tell me why u multiply 9x4 to get the 36?

Answer 20

9 = 36/4
You understand that right?

Answer 21

yes but where di that 36 come from?

Answer 22

Remember anything over 1 itself
9 = 9/1 I multiplied 4 to the top and bottom side and it doesnt change the values
I know that I will subtract 9 from the left side and it will go to the right side where -36/4

There is a rule that in order to add or substract number the denominator has to be the same so 9 has to turn into 36/4

Answer 23

once 9 turns into 36/4 I can subtract it from - 21/4

Answer 24

So basically you have to find the lowest common denominator on the left side before you bring it over to the right side to subtract from -21?

Answer 25

No you can do it after you subtract it from the left side but then I knew I was going to fall into the problem where I had to find the lower common denom. in order to subtract it so I did it beforehand. Sometimes you don't have to do that and the number substract or add much easier.

Answer 26

These types of problem require you to do a lot of little steps so make sure you write everything out just incase you make a mistake and you can see what you did.

Answer 27

thank you i get it now

Answer 28

No problem. Feel free to ask more questions.