When building a house, the number of days required to build is inversely proportional to with the number of workers. One house was built in 30 days by 20 workers. How many days would it take to build a similar house with 40 workers?

X+ y = 5 ; x - y =3 solve using linear combination

Aresearch study is studying the effects of a new drug for osteoporosis alzheimer's disease (ad) for women above the age of 65 years. a group of individuals with osteoporosis is randomized into two groups. one group is treated conventionally, and the second group is treated with the new medication. assessments are made at 3, 6, 12, 36, and 48 months. the conventionally treated group is assessed for ad using a serum blood test, and the treatment group is assessed for ad using a pet radiotracer that binds to beta-amyloid plaques. in comparing these 2 trial arms, the authors of the study may encounter which type of bias? a. selection bias on the risk of developing b. measurement bias c. confounding bias d. recall bias e. lead-time bias

25 ! what is the value of x? enter your answer in the box. x =