Please help. 4) What is the equation of the circle?
Match the expression or equation to the steps used to find the equation of the circle.
The options are shown in the picture.

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.

For the following geometric sequence, find the recursive formula. {-80, 20, -5, } i need : ')

In a class, there are 12 girls. if the ratio of boys to girls is 5: 4 how many boys are there in the class