Question

What is the equation of the graphed line in point-slope form?

A. y+3=2(x+3)
B. y=2(x+3)
C. y+3=2x
D. y-3=2(x-3)

Answer 1

Slope intercept form is:

y=mx+b, where m=slope and b=y-intercept (value of y when x=0)

m=(y2-y1)/(x2-x1) "change in x divided by change in y"

m=(3--3)/(0--3)

m=6/3

m=2

And we can see the point (0, 3) so we know b=3 thus our line is:

y=2x+3

Now point slope form is y-y1=m(x-x1), where m is the slope and (x1,y1) is any point on the line...we know slope is 2 and we can use (-3,-3) for the point so:

y+3=2(x+3)

So it is answer A.