Question

For the equation, y=-x+4 tell whether its graph passes through the first quadrant. Explain how you know.

Answer 1

@zepdrix @blahhedup101 can you guys help me?

Answer 2

Hey texas, thank you for helping me. I needed help on other questions and looked it up. I see that you also helped other students with a lot of questions :)

Answer 3

well....let me see
y = -x + 4
In y = mx + b, the slope is m and the y intercept is b.
so the slope is -1 and the y intercept is (0,4)

the x intercept can be found by subbing in 0 for y
0 = -x + 4
x = 4....x intercept is (4,0)

so start at y intercept (0,4) and come down 1 and to the right 1, then down 1, then to the right 1, and you should cross the x axis at (4,0)

Once graphed, you will see that IT PASSES THROUGH the 1st quadrant

Answer 4

Hmm, I am confused even if x is poistive it has a negative on the right

Answer 5

oh...you mean for the x intercept ?

y = -x + 4 ....sub in 0 for y
0 = -x + 4 -- add x to both sides
x = -x + x + 4 -- the x's on the right side cancel
x = 4....the x intercept is (4,0)

Is that what you are referring to ?

Answer 6

you can also check it by taking a point in quadrant 1 and checking....(2,2) is in quadrant 1.
Lets sub
y = -x + 4
2 = -2 + 4
2 = 2 (correct)

Answer 7

Yes I understand. So the two answers it could be our

Yes, for x>0 some y values are positive and

yes for x<0 some y values are positive

Answer 8

So it would be yes, for x>0 some y values are positive, right?

Answer 9

yes...x > 0 and some y values are positive

Answer 10

ok thanks... I need help on another question... Do you think you can help me?

Answer 11

I can try

Answer 12

Ok, thank you so much.
\[km \div 3-2x=4\]

Answer 13

Km/3-2x=4

Answer 14

solve for x.

Answer 15

Km/3 - 2x = 4 -- start by multiplying the whole equation by 3 to get rid of the fraction
giving us :
Km - 6x = 12 -- subtract Km from both sides
-6x = -Km + 12 -- now divide both sides by -6
x = 1/6Km - 2

sorry it took so long...got a little confused. But I finally got it

Answer 16

Thank you so much! I was getting -6+km as the answer and it was wrong. I realised that I did not multiply the whole left side by 3 and only the denominator... Thank you so much!

Answer 17

You are restoring faith in humanity by helping a 13 year old :)

Answer 18

sure thing :)

Answer 19

lol....glad to help