Write the equation in slope-intercept form of the line that has a slope of 3 and contains the point (4, 9).

Question

Here's another one, I need help ASAP on this one too!

Answer 1

The slope is 3, and so the equation is of the form y=3x+b.  The b is the y-coordinate of the point (0,b), where the line crosses the y-axis.  The line contains the point (4, 9).  To get to  x=0 you walk back 4 units, in which walk the line goes down 12 units to y=-3.  y=3x-3 is the equation.

 

Answer 2

Hi Meow,

 

 

The slope intercept form is y=mx+b

 

m=3  and (x,y)=(4,9)

 

9=(3)(4)+b

 

b=9-12=-3

 

The slope intercept form is y=3x-3