Find the equation of the line through the point (-2, 8) with slope 1/2

Question

The answer is [y=1/2x+9] but I don't understand how and I would like an exp 

 

Answer 1

Use 

 

y = mx + b

 

Given:  m = 1/2

 

y = (1/2)x + b

 

Get b using the given point (-2,8).

 

8 = (1/2)(-2) + b = -1 + b

 

b = 8 + 1 = 9

 

y = (1/2)x + 9

Answer 2

Often, problems with a point and a slope intend for you to use the point-slope form of the equation of a line:  For a point P(x₁,y₁) and a slope of m, the line is:    (y-y₁) = m(x-x₁)

 

So, plug in the values to get:

     (y-8) = (1/2)(x-(-2))

      y-8 = (1/2)(x+2)              [distribute the -]

      y-8 = (1/2)x + 1              [distribute the (1/2)]

       y = (1/2)x + 9              [add 8 to both sides[