Wirte an equation for the line that passes through (-1,-1) and (1,-5).

Question

zpupster · Answer

slope intercept formula
y=mx+b 
to find the slope
m=y2-y1/x2-x1

anonymous · Answer

Since m=-2, what does b equal?

zpupster · Answer

if you let x be 0 and solve you b-(or your y-intercept) is that

anonymous · Answer

Since m=-2, you have a point to test, and you know the equation $$y=mx+b$$
plug in a point you have (let's use (1,-5) this time), and the m you found and solve for b:$$\rightarrow b=y-mx=(-5)-(-2)(1)=-3$$

anonymous · Answer

So, the final answer is y=-2x-3?

anonymous · Answer

Yes, that's correct. 

You can verify this by putting the equation in a graphic calculator and going to the table. You'll find that both the points (-1,-1) and (1,-5) are part of the same line.

anonymous · Answer

Thanks