Name________________________

 

EVALUATING EXPRESSIONS #1--KEY

 

 

Directions:  Evaluate the expressions below when x = 4 and y = 7.  That means you should substitute a 4 in place of any x’s in the expression and substitute a 7 in place of any y’s.  After that, follow the standard order of operations to find the value of the expression.  Write that value in the space provided. 

 

Examples:        x + 2y                                      3(x + y)                       6y – 2x -3                               

                       4 + 2(7)                                    3 (4 + 7)                   6(7) – 2(4) - 3                                                                            

4 + 14                                      3(11)                           42 – 8 - 3

                          18                                             33                                  31                                                              

 

                                 

1)     xy =                    ___28___                                                         2)     x + y =             ___11___          

           

 

 

 

 

 

3)     2x + 3 =             ___11___                                                         4)     2y - 3 =            ___11___            

 

 

 

 

 

 

5)     2x + 2y =           ___22___                                                         6)     5(x+y) =           ___55___

 

 

 

 

 

 

7)     y - 2 =                ___5___                                                           8)     2y – 2x =         ___6_____                     

 

 

 

 

 

 

9)     2x + 4x + 11 =   ___35_____                                                   10)     40 – 3y + x =    ___23____