Expert: Lynn Houston - 7/13/2009

Question
I am a adult going back to school and i am having some trouble understanding these problem and how to work them out. Please Help!!!
1. Slope= 4, passing through (1,3)
2. Slope= 8, passing through (4,-1)
3. Slope= -5, passing through (-4,-2)
4. Slope= -2, passing through (0,-3)

Answer
These are all done the same way.  I'll do two to show you how and you should be able to get the rest.

You're going to use the slope intercept form y = mx + b, where m = slope and b= y intercept

you have the slope and 2 points so all you need to do is find the y-intercept.  To do that, substitute the values you know into the slope intercept equation and solve for b.

1. Slope= 4, passing through (1,3)
3= 4(1) + b (subtract 4 from both sides)
b = -1, so the equation for the line with slope of 4 and passing through points 1,3 is y=4x-1


2. Slope= 8, passing through (4,-1)

-1 = 8(4) + b (subtract 32 from both sides)
-33 = b so the eq for the line with slope 8 passing through points 4,-1 is y = 8x -33

make sense?  Now practice on the other two