Answer:
y=-2x+7
Step-by-step explanation:
slope intercept form: y=mx+b
Slope formula:
or 
You can pick any two equations. In this example, I chose the firsts 2.
(0,-7) and (1,-9)
Plug into the slope formula,
-9+7 over 1-0 which is -2/1 or -2
The m in y=mx+b is the slope, the equation above is the sloe formula meaning -2 is the slope. The b is the y, when it is at 0. The y at 0 for this equation is -7. Thus, when plugging in the equation, y=-2x-7