Which of the following expressions is equivalent to 6(94)+7+(3+2) A. 2+(3+7)+4(69)
B. 9(64)+2+(73)
C. (6+7)(94)+3+2
What properties of real numbers does this example show?

An incoming airplane is x miles due north from the control tower at an airport. a second incoming airplane is y miles due east of the same control tower. the shortest distance between the two airplanes is z miles. which of the following functions would best model the situation above?