Cho hệ các vectơ U=(1,2,7);(0,-1,-6);(2,3,8);(1,0,-5 )
a)tìm số chiều và cơ sở W của không gian con sinh bởi hệ vecto U
b)tìm tham số k để u=(2,3,k^2+1) là một tổ hợp tuyến tính của W, và suy ra [ u]w

Is the product of two rational numbers irrational or rational? first, make a hypothesis by multiplying two rational numbers. then, use variables such as x=a/b and y=c/d and the closure property of integers to prove your hypothesis.

Apoll is being conducted at a mall nothingto obtain a sample of the population of an entire country. what is the frame for this type of​ sampling? who would be excluded from the survey and how might this affect the results of the​ survey? what is the frame for this type of​ sampling? a. the frame is people who need new clothes. b. the frame is people who shop at the mall. c. the frame is people who like to shop. d. the frame is the entire population of the country. who would be excluded from the survey and how might this affect the results of the​ survey? a. any person that does not need new clothes is excluded. this could result in sampling bias due to undercoverage. b. any person who does not shop at the mall is excluded. this could result in sampling bias due to undercoverage. c. any person who does not shop at the mall is excluded. this could result in nonresponse bias due to people not participating in the poll. d. there is nobody that is being excluded from the survey.

Atotal of 505 tickets were sold for a school play they were either adult tickets or student tickets they were 55 more student tickets so than adult tickets how many adult tickets were sold ?