Hannah buys red shirts, blue shirts, and yellow shirts at a cost of $28.75 each. which expression represents the total cost, c, of the shirts, if r represents the number of red shirts , b represents the number of blue shirts, and y represents the number of yellow shirts? plz show work and explain your work : )

a. c= 28.75 ( r + b+ y )
b. c= 28.75 ( r - b - y)
c. c= 28.75 + r + b + y
d. c= 28.75 r + b+ y

You are making a battery for a science project. you have copper wire for your first electrode. you need to choose a conductor, a second electrode, and a device to plug into your battery. you have already chosen a lemon conductor. complete each statement below about the options that include a lemon conductor.

Using pert, adam munson was able to determine that the expected project completion time for the construction of a pleasure yacht is 21 months, and the project variance is 4. a) what is the probability that the project will be completed in 17 months? b) what is the probability that the project will be completed in 20 months? c) what is the probability that the project will be completed in 23 months? d) what is the probability that the project will be completed in 25 months? e) what is the due date that yields a 95% chance of completion?

Sanjay solved the equation below. which property did he use to determine that 7x+42=42 is equivalent to 7(x+6)=42 7x+42=42 7x=0 x=0