Hi there!
<u><em>FACTS</em></u><em> :</em>
<em>The general form of a y-intercept equation is : y = mx + b </em>
<em>Where "m" is the slope of the line and "b" is the y-intercept. </em>
STEPS TO ANSWER:
You want the same slope as this equation : y = 9 - 9x
This equation is the same as : y = <u>-9</u>x + 9
In this equation the slope is : -9
You want the same y-intercept as this equation : y = -10x <u>- 9</u>
In this equation the y-intercept is : -9
Your slope is -9 and your y-intercept is also -9.
This means that the equation of your new line would look like this :
y = -9x - 9
There you go! I really hope this helped, if there's anything just let me know! :)