Simplify.

1.    -(-4) = ________

2.    -(-(-(-7))) = ________

3.    -(-(-6 + 1))  = ________

4.    -a + a  = ________

5.    -b + a + b + a  = ________

6.    -(-9) + -(-(-2))  = ________

7.    -(-(-(-(-(-(-(7)))))))  = ________

8.    -4 + -(-(-4))  = ________

9.    -2.3 + 4 + 2.3 + -4  = ________

10.    -n + n + -c + h + c  = ________

11.    -(-2) + -(-(-(-4)))  = ________

12.    -(7)  = ________
 

Evaluate when a = -4 and b = -10.  Show your work in the space provided.

13.    -a + b  = ________                        14.    -b + a  = ________                     15.    -b + -b  = ________
 
 
 
 
 
 
 

16.    -a + a  = ________                        17.    -a + -a  = ________                    18.    b + a  = ________