232k views
5 votes
Which rule matches the function graphed below?

y= - 2x.
y= x+4
y = 2x
y = x -4

Which rule matches the function graphed below? y= - 2x. y= x+4 y = 2x y = x -4-example-1
User Idan Gazit
by
7.9k points

2 Answers

3 votes
Take any two points to find the slope of a line. The slope will be equal to:

(y2-y1)/(x2-x1) and any two points will do...

I'll use (-2,4) and (0,0) :P so the slope is:

(0-4)/(0--2)=-4/2=-2, now we know the slope is -2 so:

y=-2x+b (now we know b=0, but I'll use another point anyway to solve for b)

Let's use (-2,4) again...

4=-2(-2)+b

4=4+b

b=0

So the line is:

y=-2x
User Hatted
by
8.7k points
6 votes
y=-2x
We know this because the slope is -2 (slope is found using rise/run, in this case the rise is 2 and the run is -1, so 2/-1=-2), and the y-intercept is at 0 (the y-intercept is the point at which a line crosses the y-axis).

:)
User Dddsnn
by
7.7k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories