Question

how would i begin this problem...

graph the equation and identify the y-intercept.

y+x=-5

I would first rewrite that into:
y=x-5

then where do I go from there, how do I know what value to put for x??

Answer 1

I would first rewrite that into:
y=x-5
Good start!


For a linear function, you need two points to draw the line, a third point to check.

For the line
y=mx+b, put x=0, that gives you y=b at the y-axis, i.e. (0,b) is your y-intercept.
Next, you put y=0 to get the x-intercept.
You will need to solve for x=-b/m.
With two points, you can graph the line.
Alternatively, you can make a table of values of x and y for at least two to three points.
In your example, m=1, and b=-5.

You'll have at least the two intercepts. You can make more points by putting x=1, x=2, ... until you have enough of them. lol.

Answer 2

Sign dropped?

Doesn't y+x=-5 rewrite as y=-x-5?

Answer 3

Thanks jim, indeed. I missed that.
So
y+x=-5
rewrites as
y=-x-5
The y-intercept is still -5, but the slope m is now -1.

Answer 4

thanks