The expression below shows a number in expanded form. What is the standard form of the number? 2 × 10 + 3 × 110 + 9 × 1100 + 7 × 11000

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.

Place the following steps in order to complete the square and solve the quadratic equation,

Complete the solution of the equation. find the value of y when x equals to 28 x+3y=28