140,366 views
40 votes
40 votes
Which is the correct equation of the line for the following graph?

Which is the correct equation of the line for the following graph?-example-1
User FarrEver
by
3.0k points

1 Answer

17 votes
17 votes

Answer:

(c) y = -3x +6

Explanation:

The equation can be written in slope-intercept form when we know the slope and the y-intercept.

Slope-intercept form

The slope-intercept form of the equation of a line is ...

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

Y-intercept

The y-intercept is the y-value where the line crosses the y-axis. It is 6. This eliminates choices A and D, leaving choices ...

  • y = 3x +6 . . . . . choice B
  • y = -3x +6 . . . . .choice C

Slope

The line goes down to the right. This is a negative slope, eliminating choice B.

The equation of the line is y = -3x +6.

__

Additional comment

The line intersects the x-axis at x=2. This means the "rise" of the line is -6 units for a "run" of 2 units. The numerical value of the slope is ...

m = rise/run = -6/2 = -3

Now, we know the parameters of the equation are m=-3, b=6, and the equation of the line is

y =-3x +6

User Marienke
by
3.1k points