Answer:
Step-by-step explanation:

-infinity, positive infinity
The slope can sometimes be called the gradient, and the equation for the gradient is (y2 - y1)/(x2 - x1). So therefore, you'd do: (-8 - 7)/(4 - -5) which is (-15)/9) which is -1 2/3 or -1.6 (recurring), which is your answer. I hope this helps! Let me know if I've confused you :)
The complete question in the attached figure
we know that
<span>The measure of the external angle is the semidifference of the arcs that it covers.
so
</span><span>m∠BED =(1/2)*[mAC-mBD]-------> solve for mBD
mBD=mAC-2</span>m∠BED
mBD=80-2*25--------> mBD=30°
the answer ismBD=30°