equation for slope

Question

A line passes through the point and has a slope of . Write an equation for this line.

Answer 1

Hi Mandy;

Point-slope formula is...

y-y₁=m(x-x₁)

m=slope

You can input the point provided either as (x,y) or (x₁,y₁).  I always do the latter.

Let's me provide an example.

slope -4/5

point (5,3)

y-3=(-4/5)(x-5)

y-3=(-4/5)x+4

Let's add 3 to both sides...

y-3+3=(-4/5)m+4+3

y=(-4/5)x+7

The equation is now in slope-intercept form...

y=mx+b

m is the slope.

b is the y-intercept, the value of y when x=0. 

Answer 2

Line passes through ( X_1, Y1 )  with slope m

 

  Y = m X + b 

 

 

   b = Y₁- mX₁ 

 

  Y = mX + ( Y₁- m X_{1 )}