how to find formula from point and slope

Question

how to find formula from point (-1,0) and slope -4

Answer 1

Given a point (x₁, y₁) and slope m, use the

point slope formula to find the equation of

the line:   y-y₁ = m(x-x₁)

 

Example:  Find the equation of the line through

(5, -2) with slope 4

 

y -(-2) = 4(x-5)

distribute the 4 through the parenthesis

y + 2 = 4x - 20

subtract 4x from both sides

-4x + y + 2 = -20

subtract 2 from both sides

-4x + y = -22

 

Do the same thing with (x₁, y₁) = (-1, 0) and m=-4

y - 0 = -4(x-(-1))

Answer 2

you mean find equation of line having that slope & that x-intercept?

 

I suggest you use the POINT SLOPE form of equation of a straight line.  Easy!