Question

How do you write an equation of the line that passes through the given (3,4); m=-4?

Answer 1

`y = -4x+16`

Explanation:

You have 2 choices for the equation of a straight line:

• Substitute into the "point-slope" form `y-y_1=m(x-x_1)` which involves one one substitution and some simplifying.

• Substitute into the "slope-intercept" form to find `c` first. This involves two substitutions.

My choice is the first option. You have `m = -4 and (3,4)`

`y-y_1=m(x-x_1)" "larr` leave `x and y`
`color(white)(xx)darrcolor(white)(xx)darrcolor(white)(xx.x)darr`

`ycolor(blue)(-4) = -4(x-3)`

`y = -4x+12color(blue)(+4)`

`y = -4x+16`