Lance wants to find the total length of 3 boards. he uses the expression 3 1/2+(2+4 1/2). how can lance rewrite the expression using both the associative and cummutative property of addition?

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.

Simplify a7/a4 a) 1/a3 b)-a/a2 c)a4/a3 d)a3

The table shows the total distance that myra runs over different time periods. which describes myra’s distance as time increases? increasing decreasing zero constant