Question

What is the equation in point-slope form of the line passing through (2, 5) and (–1, 8)?

y + 5 = 1(x + 2)

y + 8 = –1(x – 1)

y – 5 = –1(x – 2)

y – 8 = 1(x – 2)

What is the equation of the line in standard form that passes through the point (3, –2) and is parallel to the line y = –4x + 1?

x + 4y = 10

x – 4y = –10

4x – y = –10

4x + y = 10

Answer 1

do u know how to compute the slope between two points??

Answer 2

not very well no. could you please explain?

Answer 3

the formula is
\[ \large \frac{y_0-y_1}{x_0-x_1} \]
for given points \((x_0,y_0)\) and \((x_1,y_1)\)

Answer 4

u have (2,5) and (-1,8) try it!!

Answer 5

i'm completely stuck. could you walk through the problems for me?

Answer 6

OK. the slope would be
\[ \large m=\frac{8-5}{-1-2}=\frac{3}{-3}=-1 \]
got it???

Answer 7

Okay, i got that part.

Answer 8

OK. this is the slope of the line u r looking for.

Answer 9

the line in slope-point form is
\[ \large y-y_0=m(x-x_0) \]

Answer 10

Right, i know that part.

Answer 11

u already have m=-1 and two points (-1,8) and (2,5).
u can choose either one of the two points!!!
choose one!!

Answer 12

Okay, (-1,-8)

Answer 13

no (-1,8)

Answer 14

then u have \(m=-1\) and the point \((-1,8)=(x_0,y_0)\). replace this into
\[ \large y-y_0=m(x-x_0) \]

Answer 15

okay, did that.

Answer 16

show me!!

Answer 17

I'm doing it on my homework. But, i think i just figured out what i did for the first one. what did you get?

Answer 18

ok it should be
\[ \large y-8=-1(x-(-1)) \]
or
\[ \large y-8=-(x+1) \]

Answer 19

thank you so much for your help. what did you get for the second one?

Answer 20

u have the line
\[ \large y=-4x+1 \]
it has the form slope-intercept
\[ \large y=mx+b \]
so m=-4

Answer 21

okay

Answer 22

it just as above. u have m=-4 and one point (3,-2). do what u did before but this time do the algebra.

Answer 23

Yeah thats where i lack. Okay, thank you for your help.

Answer 24

u r welcome