Joselyn is a manager of a window installing company. She ask two professional installers, Mark and Anna, in install all the windows in a large home. Mark can install all the windows in 16 hours. Anna can install all the windows in 9 hours. Joselyn wants to know how long it will take them to install all the windows in the home if they work together. Write an equation and solve for the time it will take Mark and Anna to install all the windows together. Explain each step.

Jeffery conducted a survey in his school and found that 30 of the 50 eighth grade students' favorite subject is mathematics. based on the results, jeffery concluded that out of the 200 students in his school, 120 students' favorite subject is mathematics. select the statement that is true about jeffery's conclusion. a. jeffery's conclusion is not valid because the sample was biased since only 200 students were surveyed. b. jeffery's conclusion is valid because the sample was random since all of the students were eighth grade students. c. jeffery's conclusion is valid because the sample was random. d. jeffery's conclusion is not valid because the sample was biased since all of the students were eighth grade students.

Lin is writing an equation to model the proportional relationship between y, the total cost in dollars of downloading videos from a website, and x, the number of videos downloaded. she knows that the total cost to download 3 videos was $12. her work to find the equation is shown below. joylin’s work step 1 k= 3/12= 0.25 step 2 y= 0.25x where did joylin make her first error?

If your teacher tells you to do questions 6 through 19 in your math book for homework, how many questions is that