Question

What is the equation of the line that passes through the point (3,-6) and has a slope of -3?

Answer 1

y = -3x+3

Explanation:

Remember that y = mx+c

The slope is m aka the gradient and we know that that's -3.

So just chuck it into the equation:

y = -3x + c

We still have to find c (which is the y intercept)

So substitute the point (3,-6) into the equation

We will have: -6 = -3(3) +c

Once you do algebra you'll get 3=c

So substitute that back into the equation (without the point (3,-6) since we only need the equation)

y = -3x + 3

Answer 2

y = -3x + 3

Explanation:

the equation of a line in point-slope form is.

y -
`y_1` = m(x -
`x_1`)
y - (-6) = -3 (x - 3)

y+6 = -3x+9