Will somebody make sure that i'm doing these questions right.

What signals you that factoring by grouping is the best method to use when factoring a problem?

What is the slope of the line that contains the points (-2,1) and (0,-3)

Organic apples are on special for $1.50 per pound. does total cost vary inversely or directly with the number of pounds purchased? find the cost of 3.4 pounds of apples. a. inversely: $5.10 b. directly; $5.10 c. inversely: $2.27 d. directly; $2.27