The calculation needed to find the cost of the factory tour was $5(29 students). Melissa used the expression $5(20 9). Mrs. Garcia used the expression $5(14 15). Explain why Mrs. Garcia’s method may be more difficult to do mentally.

Two technicians are discussing how to test a car's exhaust by holding a small piece of paper within an inch of the tailpipe mouth. technician a says that if the paper is vibrating due to a "puffing" output from the tailpipe, this signals a smoothly running engine. technician b says that if the paper is being drawn toward the tailpipe, this could indicate burned exhaust valves. who is correct? a. technician b b. both technicians a and b c. technician a d. neither technicians a or b

In this food web, which group would increase in number if snakes were eliminated? a. producers b. decomposers c. primary consumers d. secondary consumers e. tertiary consumers

Why are gold and platinum used for jewelry