Question 305119
what is the slope intercept equation for the line with the given slope that contains the points 
m=-3;(1,-5) 
I know that the answer is -3-2 but how do I reach that answer?

The slope intercept form of a line is y = m*x + b where m is the slope and b is the value of y where the line intercepts the y-axis (that is when x=0). 

Since m = -3 we have:

1.) y = -3*x + b.

The line passes through the point (1,-5) so when x = 1, y = -5. Substituting these values for x and y in equation 1.) we have:

-5 = -3*1 + b

-5 = -3 + b
b = -5 + 3 = -2

With b = -2 equation 1.) becomes:

y = -3x - 2