Question

A line perpendicular to y=1/4x+3 passes through the point (0,6). Which other point lies on the line?
A) (4,-2)
B) (3,-6)
C) (0, -6)
D) (-2, 2)

Answer 1

can u tell me which chapter this ques is related to

Answer 2

So we need to find the line perpendicular to y=1/4 * x+3 that goes through (0,6)
First job is to identify the slope of y=1/4 * x+3.

Answer 3

i have no idea... i got a math packet for spring break and all it says is chapters 1 through 9

Answer 4

ok...

Answer 5

Hint: The slope of y=mx+b is m.
So the slope of y=1/4 * x+3 is?

Answer 6

1/4?

Answer 7

Yes.
Now to find the slope of the perpendicular line we must flip that fraction and then take the opposite of value of that flipping.

Answer 8

So when you flip 1/4 you get?

Answer 9

4

Answer 10

and you take the opposite of that number you get?

Answer 11

1/4?

Answer 12

flip is reciprocal
opposite you change signs

Answer 13

1/4 is not the opposite of 4

Answer 14

-4 is the opposite of 4

Answer 15

ooooo ok so its -1/4?

Answer 16

-4 is the slope of the perpendicular line.

Answer 17

oooo ok

Answer 18

no

Answer 19

you flip 1/4 and then take the opposite of that result.
the flipping of 1/4 is 4
the opposite of that flipping is -4.

Answer 20

ok

Answer 21

So we know know the line is
y=mx+b
where m is -4
y=-4x+b

Answer 22

we need to find b

Answer 23

we know this line goes through (0,6)

Answer 24

ok

Answer 25

(0,6) is actually the y-intercept

Answer 26

since the x value is 0 there

Answer 27

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

Answer 28

your b is ? take a guess

Answer 29

6

Answer 30

yes
so your line that is perpendicular to y=1/4*x+3 is y=-4*x+6

Answer 31

ok

Answer 32

and that goes through (0,6) of course

Answer 33

now of the points listed which point satisfies y=-4x+6

Answer 34

so can i basically put in the answer choices and see if it works?

Answer 35

For example, you are trying to see which point gives you the same thing on both sides.
Will (4,-2) work?
Replace x with 4 and y with -2.
y=-4x+6
-2=-4(4)+6
-2=-16+6
-2=-10
so the point (4,-2) is definitely not on y=-4x+6 since we know -2=-10 is definitely not true.

You are looking for a point that will make the equation true. That point that makes the equation true is a point on the line.

Answer 36

Its B right?

Answer 37

(3, -6)?

Answer 38

Yes actually.
y=-4x+6
replace x with 3
and y with -6
-6=-4(3)+6
-6=-12+6
-6=-6
totally true
so (3,-6) is totally on the line

Answer 39

ok great thank you very much!

Answer 40

np