1.   Three planes can
    A. intersect in a line. B. intersect at one point.
    C. have no points in common. D. All of the choices are true.
    Hint

  2.   If you solve the following system of equations by substitution, which statement is true?

x = z
x - 2y + z = 6
2x + y - 2z = 1

    A. Neither method will work. B. Both methods will work.
    C. You can substitute x for z into the second and third equations. D. You can substitute z for x into the second and third equations.
    Hint

  3.   Solve the system of equations by substitution.

x = z
x - 2y + z = 6
2x + y - 2z = 1

What is the value of x + y + z?
    A. 11 B. 10
    C. 8 D. 9
    Hint

  4.   In 1999 Bob scored 824 points as a college basketball player by hitting 372 of his attempts. If he made 60% of his 200 3-point field goal attempts, how many 1-, 2-, and 3-point field goal baskets did he make?
    A. (40, 120, 212) B. (212, 40, 120)
    C. (40, 212, 120) D. (120, 40, 212)
    Hint

  5.   Solve the system of 3 equations by substitution.

x = 3y + 2z
2x + 3y + 2z = 3
-x + y - z = 6

    A. no solution B. infinite solutions
    C. (1, 3, -4) D. (8, 4, -2)
    Hint