Question

Write an equation of the line for (0,-1) , (8,-5) using y=mx+b

Answer 1

`\boxed{ y=-2x-1}`

Explanation:

The statement provides us two points (P):

`P_1= (x_1,y_1)=(0,-1)\\P_2= (x_2,y_2)= (8,-5)`

And the point-slope equation of the line.

`y=mx+b`

where:

`\displaystyle{m=(\Delta x)/(\Delta y) = (x_2-x_1)/(y_2-y_1)\\=(8-(0))/(-5-(-1))= (8)/(-4)=-2}`

thus:

`y=-2x+b`

Since we are only asked to use the point-slope equation, to obtain b we will have to evaluate one of the two points.

in
`(0,-1)`

`-1=-2(0)+b\\b=-1`

`\implies y=-2x-1`

Therefore, we have found the solution to the exercise

`\text{-B$\mathfrak{randon}$VN}`