Point-slope form is as follows:
y-y1=m(x-x1)
To find the slope we can use the formula:
m=y2-y1/x2-x1
We can then insert our values given in the question:
(-7,1)=(x1,y1) and (-3,9)=(x2,y2)
Inserted into the equation becomes:
m = 9-1/-3-(-7)
m = 2
Therefore, our slope equals 2 and we can find the rest of the equation using the aforementioned formula of:
y-y1=m(x-x1)
Insert our values:
y-1 = 2(x-(-7))
y-1 = 2(x+7) <— (negatives make a positive)
We can then multiply what’s inside the bracket by 2:
y-1 = 2x+14
And then to get y alone on the left side we will add 1 to both sides leaving us with:
y=2x+15
Therefore, y=2x+15 is your answer.