Question

Line AB contains points A(3,-2) and B(1,8). the slope of line AB is?

Answer 1

The slope of a line is $\frac{y_2 - y_1}{x_2 - x_1}$. We have the points (3, -2) and (1, 8). Let's substitute those into the formula. 
$\frac{8 - (-2)}{1-3}$
subtracting a negative is the same as adding, so that makes our equation
$\frac{8+2}{1-3}$
$\frac{10}{-2}$
slope = -5