1) simplify 9 - {x - (7 + x)}

2) simplify (-5) + (-4) + (7).

3) evaluate a^2 for a = -3.

4)simplify and determine the coefficient of (-1/3x)().

5)evaluate 5x3 + 2 for x = -1.

1. 9 - { x - (7 + x)}
    9 - { x - 7 - x}
    9 - { -7}
     9 + 7
       16 <===

2 (-5) + (-4) + 7 =
    -5 - 4 + 7 =
      -9 + 7 =
        -2 <==

3. A^2when A = -3
   (-3)^2 =
    -3 * -3 =
     9 <==

4. (-1/3x)(3y)(-2x) =
    (-1/3*3*-2)(xyx) =
     (-1*-2)(x^2y) =
        2x^2ythe coefficient is 2

5. 5x^3 + 2when x = -1
    5(-1^3) + 2 =
    5(-1) + 2 =
     -5 + 2 =
      -3 <==