Some quetions I'm not getting.

[Kaya]

Write an equation in slope-intercept form of the line that is parallel to the graph of each equation and passes through the given point.

y= 4; (2,5)





Determine wheter AB and CD are parallel, perpendicular, or neither.
A(4,3), B(5,2), C(8,3), D(9,2)

Write an equation in slope-intercept form of each line
A. passes through the point at (4,2) and is parallel to the graph of 5x-27=6
B. perpendicular to the line through points at (1,2) and (8,6) and passes through the point at (0,5)


Please help !!! :eek:

[Jess]

okay, first problem. y = 4 is a horizontal line. if the other line that passes through (2, 5) is parallel to y = 4, it also has to be a horizontal line.

y = 5

(note: I might be wrong. Yeah, I'm in 11th grade and I might have gotten this wrong. sorry.)


second problem

you need to figure out the slope of AB and CD. if the slopes are equal, they are parallel. if opposite reciprocals, they are perpendicular. if neither, neither.

you know how to figure the slope of a line, right?



third problem
A. get that equation...um is there a y? if yes get y by itself. the slope of the new equation would be equal to that equation. plug in the x and y value of the point into that equation. that would figure out the y-intercept.

B. figure out the slope. the y intercept is at 5.




sorry I didn't work it out for you but I want you to try it do it yourself. anymore questions, feel free to ask. and one thing...I might not be very clear in my directions and I might be wrong. so REALLY sorry about that (makes me feel stupid...)



edit: if my help doesn't help, you can look at this: http://www.purplemath.com/modules/strtlneq.htm

[Kaya]

Ok. I finished them. I have one more problem I forgot to add in.




40. Determine whether quadrilateral JKLM is a rectangle if its vertices are J(0,5), K(9,2), L(7,-4), and M(-2,-1)



I keep trying and trying...but I fail

[the wasabi]

find slopes of jk, kl, lm, and mj to show that intersecting lines are perpendicular and lines not touching each other are parallel.

then use distance form. to show that parallel lines are same length.

[Jess]

Ok. I finished them. I have one more problem I forgot to add in.




40. Determine whether quadrilateral JKLM is a rectangle if its vertices are J(0,5), K(9,2), L(7,-4), and M(-2,-1)



I keep trying and trying...but I fail

figure out the slopes. if JK and LM are parallel and JM and KL are perpendicular, then it would be a rectangle.