Question

Write the equation of the line perpendicular to 9x+2y=18 and passes through the point (1,4).
Possible answers- a) 9x-2y=1, b) 2x-9y=-34,
c) 2x+9y=38, d) 9x+2y=17

Answer 1

do you know how to find the slope of 9x + 2y=18

Answer 2

no

Answer 3

do you recognize the point-slope form?

y=mx+b
where m is the slope and b is the y-intercept

Answer 4

yes so would i not put anything in the slope spot?

Answer 5

no. you have to do a little algebra such that it would look like that form

Answer 6

so lets start by subtracting 9x on both sides.
what do you have now?

Answer 7

I'm not sure what the set up of the equation is

Answer 8

9x +2y=18
-9x -9x
--------------
2y=-9x +18

does this make sense to you?

Answer 9

yes

Answer 10

now divide both sides by 2 so that y is isolated on the left side

Answer 11

Wouldn't that cancel out the 2?

Answer 12

correct
2y=-9x +18
-- -------
2 2

y=-9/2x +9

do you see why i did this?
and doesnt this look familiar now?

Answer 13

no

Answer 14

I don't recall

Answer 15

i meant slope-intercept form

y=mx+b

Answer 16

oh yes

Answer 17

so whats the slope?

Answer 18

9?

Answer 19

\[y=-\frac{ 9 }{ 2 }x +9\]

Answer 20

what's the slope?

Answer 21

I don't know. I don't understand this

Answer 22

whats the "m"

Answer 23

I just said I don't know

Answer 24

its -9/2