Given: and Prove: slope of × slope of = -1 Statements Reasons 1. is similar to Given 2. Property of similar triangles 3. slope of slope of Definition of slope 4. slope of slope of Multiplying the slopes 5. Substitution property of equality 6. slope of slope of = -1 Simplifying the right side The table shows the proof of the relationship between the slopes of two perpendicular lines. What is the missing statement in step 5? A. B. C. D.

Which system of linear inequalities is represented by the graph? + l tv x-3y > 6 and y > 2x o x + 3y > 6 and y o x-3y > 6 and y> 2x o x + 3y > 6 and y > 2x + 4 la +

Two customers went to a post office. first customer paid $12 for 14 and 5 envelopes the second paid 24.80 for 10 postcards and 15 envelopes. what is cost of each envelope?

The position of a moving particle is given by the position function: f(t)=-9t-t^2-0.2t^3+0.1t^4 0 a. at what time does the particle reverse direction? b. when is the displacement positive? (round one decimal place and answer in interval notation) c. when is the displacement negative? (round one decimal place and answer in interval notation) d. when is the particle’s acceleration positive? (round one decimal place and answer in interval notation) e. when is the particle’s acceleration negative? (round one decimal place and answer in interval notation)