Question

What is the equation of the line with a slope of 4 and passes through the point (1, -4)?

Answer 1

Answer: y = 4x - 8

Step-by-step explanation:

The best way to go about this is to first put the information you know into point-slope form, which is:

$y-y_{1} =m(x-x_{1})$

$y_{1}$ and $x_{1}$ represent the values of our point (1, -4), so:

$y_{1}=-4$, and $x_{1}=1$.

$m$ represents our slope of 4, so:

$m=4$

From this, we can plug in our values:

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

A little simplification and distrobution takes us to this:

$y+4=4x-4$

Then simply subract 4 from both sides to get this:

$y=4x-8$

An easier way to reason this is to visualize the line in your head and figuring out what the y-intercept is so you can go strait into the $y=mx+b$ form where b is the y-intercept.

Answer 2

Answer:

y=4x-8

Step-by-step explanation:

m=4 (1,-4)

-4=4(1) + c

-4=4+c

-4-4=c

-8=c

y=4x-8