Verified answer

To solve for the x-intercept, you'll plug in 0 for y and solve. This makes sense because for x-intercepts, the ordered pair (x,y) y has to be zero because it crosses the x-axis.

0=-x-9

9= -x

-9=x

To solve for the y-intercept, you'll plug in 0 for x and solve. This makes sense because in y-intercepts, when you're looking at the graph, the x has to be zero in order for it to cross the y-axis.

y= -0 -9

y=-9

ok. y = mx + b

the y-int is "b" in that format, so the y-int would be "-9".

if you substitute in "0" for y in the equation, you will get the x-int (because wherever the line crosses the x axis the y value will be zero). therefore...

y = -x - 9

0 = -x - 9

*add 9*

9 = -x

*divide by -1*

-9 = x

...so the x-int is -9, also.

hope i was able to help. :)

imagine x=0 because at the y intercept, the x coordinate is zero

then

y= -(0) - 9

y=-9

the y intercept is -9