You can put this solution on YOUR website!
how would i write the equation for a pair of parallel lines with the points:
(-4,-1), (1,1) [one of them] and (-2,-5), (3,-3) [the other]???
You're right the lines would be parallel.
The slope of the first line can be found with the slope formula:
, where (x1,y1) and (x2,y2) are given points and m is slope.
For (-4,-1) and (1,1) the slope is:
The slope of the other 2 points is also 2/5. All parallel lines have the same slope.
Once you have a slope and a point you can write the equation of a line using the point-slope formula
, m=slope, and (x1,y1)=any point on the line:
For the first set of points, let m=2/5 and (x1,y1)=(1,1)
For fun, you can use the other point to get this same equation.
I'll let you prove that I'm right about the slope of the other two points is also m=2/5 (x1,y1)=(-2,-5)
Now use the other point to get this same equation for fun.