Question

Write the equation of the line passing through the point (2,-1) with a slope of -3

Answer 1

We have a slope of -3 and a point of (2,-1) so this line can be expressed as:

slope intercept form:  y=mx+b where m=slope and b=y-intercept...

y=-3x+b, using point (2,-1) we can solve for b

-1=-3(2)+b

-1=-6+b

b=5 so 

y=-3x+5

.....

We can also express this in point slope form:  (y-y1)=m(x-x1)  we know m=-3 and (x1,y1)=(2,-1)

(y+1)=-3(x-2)

....

Finally we can express the line is standard form:  ax+by=k

If we look at the y=mx+b that we had earlier we can simply rearrange it into standard form...

y=-3x+5  add 3x to both sides and we are done :P

3x+y=5

Answer 2

Y= 2x-3 i think, but i may be wrong