Key to the Practice Midterm

1.  A. False, subtraction is not associative.

B.  True, if x is an integer then it is also a rational number

C.  True, by the comm prop of +

2.  A)  -x -10y

B)  -3x² -x -4

3.  Let x be the width, then the area A = w(3w - 10)

4.  The set of all x that are elements of the real numbers such that x is greater than or equal to -3.  (Sketch done in class)

5.  A.  -14

B.  4

C.  46

6.  let x be the number.  x + 1 + 2/x

7.  A)  x = 1

B)  x = 2/5