# Slope of a line.A line contains the points (a-4, b+4) and (a, b). What is the slope of the line ?

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The slope of a line passing through (x1, y1) and (x2, y2) is (y2 - y1)/(x2 - x1)

Here the line passes through (a-4, b+4) and (a, b).

The slope of the line is (b + 4 - b)/(a - 4 - a)

=> 4/(-4)

=> -1

**The slope of the line is -1.**

The slope of the line that passes through 2 given points has the formula:

m=(y2-y1)/(x2-x1)

We'll put x1 = a-4, y1 = b+4 and x2 = a, y2 = b.

We'll substitute them in the formula of the slope:

m = [b-(b+4)]/[a - (a-4)]

We'll remove the brackets and we'll get:

m = (b-b-4)/(a-a+4)

We'll eliminate like terms and we'll have:

m = -4/4

m = -1

The slope of the line that passes through the given points is m = -1.