For this case we have that by definition:

So:

We apply distributive property that states that:

In addition, we take into account that:


Answer:

Option B
Answer:
In order to find the slope, you need to find the difference in the x values and the difference in the y values. To do this, you write out y2-y1/x2-x1, insert your x and y values, and get your answer. Then, you find your y-intercept (where the x value is 0).
Start by distributing the - 1/3 which is the same as dividing the entire parentheses by 3 which results in (3x+10)