i need to find the intercepts and use them to graph this equation: y= -4-4x

Question

I am taking Math116 with University of Ph online, I am really struggling with graphing linear equations.  Taking Math online is not something I would recommend if you are a visual learner like I am.

Answer 1

y = -4 -4x

rewrite it in the y = mx + b format

y = -4x - 4

m = -4   which means -4/1   and b (y-intercept ) = -4 or (0,-4)  a point on the y-axis

to graph it start at the point (0,-4) count down 4 on y-axis and then go to the right 1

you have 2 points and can graph it now

Answer 2

to find the intercepts you can plug 0 in where you see x and then solve for 

and. . .

plug 0 in for y and then solve for x

Let's start with x=0 plug in 0 where you see x in the equation

y=-4-4*0

then we solve for y

4 times 0 is 0 so we can get rid of that all together

so y=-4 when x =0

You can put that point on the graph as (0,-4)

 

Now we need to do the same thing with y=0 again, plug in 0 where you see y

0=-4-4x

add 4 to both sides

4=-4x

divide both sides by -4

x=-1

so when y=0 x=-1

You can put that on the graph as (-1,0)

Here is a graph. Notice how the line passes through both the x and y axis at the points above. Those are the intercepts. x-intercept is -1 and y-intercept is -4