Question

medal for who HELPS not for who gives an answer.

Answer 1

Question?

Answer 2

Andy found these three ordered pairs for the equation y = 65x +250: (0, 250), (5,575), and (10,900). When he graphs these, what is the minimum range for the y-axis?

0 to 900

0 to 250

0 to 10

65 to 250

Answer 3

Well, we know that since y=65x+250, there are no negative signs, and we also know that when the function is at x=0, the y value is 250.
He has to go 0 to 900 to include all the points because if he didn't, and only went from 0 to 250, he wouldn't be able to plot the points (5,575) or (10,900)
so he has to go 0 to 900.
do you understand?

Answer 4

So (5,575) and (10,900) do not fit with the equation?

Answer 5

Or rather the equation isn't true with those two ordered pairs?

Answer 6

No. The equation is true, but if you can only count from 0 to 250, can you go to 575? 900?
No you can't because you don't know those.
But if you know all the way up to 900, then you can get every value from 0 to 900.

Answer 7

Oh my bad, i read your previous post wrong. tyvm.

Answer 8

No problem; anything else?

Answer 9

Can you help me with another one? It's a quick one too.

Answer 10

Sure; go ahead and type it up.

Answer 11

Orlando went to a game room, which charged $3.00 admission plus $0.50 per game token. The equation representing his cost is y = 0.50x + 3. When he graphs this, what should be the label on the x-axis?.

number of tokens

cost per token

admission

total cost

Answer 12

Okay, first off, what do you think 'y' represents?

Answer 13

the total cost

Answer 14

Correct, so what does the problem tell us the cost varies with?
keep in mind that you only have to pay admission once.

Answer 15

cost per token

Answer 16

The cost per token is the same, but what varies is how many tokens you buy.

Answer 17

ooooh, thanks.

Answer 18

Do you see it?

Answer 19

Yes, I see. have time for more problems?

Answer 20

Yeah, go ahead and throw a few more on here.

Answer 21

What is the slope in the equation: y = 6x - 300?
Im guessing you have to use the equation y = mx +b?

Answer 22

Correct

Answer 23

so what would be the first step? to add 300 to both sides?

Answer 24

or do you want to get both the variables on one side?

Answer 25

You don't have to do anything but look at the equation.
What is 'm' in this situation?

Answer 26

6

Answer 27

yup, and we know that 'm' is the slope. So that problem is complete.

Answer 28

Oh lol.

Answer 29

Which of the following are the x and y intercepts of the equation 2x -2y = 3?

(2, 0), (0, 2)

(1.5, 0), (0, -1.5)

(2/3, 0), (0, -2/3)

(3, 0), (0, -3)
__________________________________________________________________________________
Would you just test each one to see which one fits?

Answer 30

You could test, or you can do it mathematically.
First, lets rearrange the equation.
2x-2y=3
-2y=-2x+3
2y=2x-3
y=x-3/2

Answer 31

What happens when x=0?

What happens when y=0?

Answer 32

It eliminates one of the variables..? making the problem solvable?

Answer 33

Erm, take x=0, and plug in 0 for x in the equation and see what you get for y.

Answer 34

y = 0 - 3/2

Answer 35

y = -3/2

Answer 36

Yup. So when x=0, y = -3/2 ; We can express that as an ordered pair (0, -3/2) which is one of your answers.

Answer 37

Now take y=x-(3/2) and take y=0, solve for x, and write it as an ordered pair.

Answer 38

0 = x -3/2
0 + 3/2 = x -3/2 + 3/2
3/2 = x

(3/2, 0)

Answer 39

Correct. do you understand why we said x,y=0 in the equations?

Answer 40

Yes, to substitute a variable in the equation right? (Also because its the easiest to solve with)

Answer 41

Not exactly.
In the first case, when we intercepted the y axis, the problem asked for the value of y when we did that. to get that, we had to say, 'hmmm when we intercept the y axis, x=0, so lets set x=0 in the equation and solve for y!"

Answer 42

Like wise, when the line crosses the x axis, y is equal to zero, so we substituted in y=0 for the equation to be able to solve it.

Answer 43

Ooh I see now.

Answer 44

It's important to think of it geometrically so you can use your intuition for these problems.

Answer 45

Which of the following equations is the slope-intercept form of 4x - 2y = 8?

y = 2x - 4

y = -4x - 8

y = 1/2 x + 2

y = -2x + 4
____________________________________________________________________________________
Is this correct.?
4x -2y = 8
-2y = -4x + 8
-y = -2x + 4
y = 2x -4

Answer 46

Yup. That's correct.

Answer 47

Do you have time for 1 or 2 more?

Answer 48

Yeah, go ahead.

Answer 49

Which of the following best describes the technique used to graph the equation using the slope and y-intercept? y = 5x + 10

Mark a point at 5 on the y-axis, go up 10 and left one and mark this point

Mark a point at 5 on the y-axis, go up 10 and right one and mark this point.

Mark a point at 10 on the y-axis, go down 5 and right one and mark this point.

Mark a point at 10 on the y-axis, go up 5 and right one and mark this point.

Answer 50

Well, first off, when we look at the equation y=5x+10, we know that when x=0, y is equal to 10 [like last problem]
so if we were to graph this, we would go 10 units on which axis?

Answer 51

the y-axis

Answer 52

correct, now is our slope positive or negative?

Answer 53

y=5x+10
y=mx+b
m=slope

Answer 54

my bad i lost connection to the internet. And thank you.

Answer 55

No problem. Do you understand why the answer is the fourth one?

Answer 56

Yes

Answer 57

Last one..
_______________________________________________________________________________
Which of the following best describes using a slope of -5/10 on a graph?

Move left 5 and up 10.

Move down 5 and left 10.

Move down 5 and right 10.

Move up 5 and right 10.
_______________________________________________________________________________
I'm guessing it's the first option

Answer 58

Remember, slope is rise / run, so if your slope is -5/10, you go Down (b/c its negative), and to the right 10 units.

Answer 59

*down 5 units

Answer 60

Oh i didn't know if rise counted for negatives too

Answer 61

Ohyeah it counts all the time. Else we'd only have positive slopes in the world. No downhill areas ever lol

Answer 62

the negative sign indicates that it's going down. The 5 means its moving vertically 5 units, the denominator means its moving to the right 10 units.
The sign denotes which direction it moves.

Answer 63

Well, thank you for your time, it really helped! tyvm

Answer 64

Yeah np, glad to help others understand this stuff. Good luck in your studies.