What is the slope of this line? someone, anyone.

For this case we have that by definition, the slope of a line is given by:

Where:

andare two points through which the line passes.

According to the figure we have to, the line goes through:

Substituting we have:

Thus, the slope of the line is -1.

use distributive property on all like terms and change your signs if you have a double negative or if you have positive/negative