Thread: Linear Equations: Point-slope Form

Hi, I'm having trouble figuring out these equations. I can find the answer when the numbers are whole numbers, but when they're fractions and decimals, I always get them wrong.



"Write an equation of the line that passes through the given points."

a) (-1/2, -5); m = -1/2
b) (-2, 1); m = 1.5
c) (1.5, 2) and (-1.5, -7)

I appreciate any help given!

You are given the slope and a point, so you need to put this in point slope form and solve for y.

y - y1 = m ( x - x1)

y - ( -5) = -1/2 (x - (-1/2))

y + 5 = -1/2x - 1/4

y = -1/2x - 21/4

Originally Posted by dashreeve

You are given the slope and a point, so you need to put this in point slope form and solve for y.

y - y1 = m ( x - x1)

y - ( -5) = -1/2 (x - (-1/2))

y + 5 = -1/2x - 1/4

y = -1/2x - 21/4

How did you get from -1/4 to -21/4 though?

Originally Posted by 4AM

How did you get from -1/4 to -21/4 though?

Typo.

Originally Posted by 4AM

How did you get from -1/4 to -21/4 though?

subtracting 5 from each side, 21/4 or 5 and 1/4