Question 21396
If you have determined the slope of the line
M=   Y2-Y1
    --------  =  -10 - (-5) / 3-2 = -15
     X2-X1

Then use this formula first
Y-Y1= m(X-X1)

y- (-10)= -15(x-2)
y + 10 = -15x + 30
Y= -15X +30-10
Y= -15X +20   (SLOPE INTERCEPT FORM).