4(2z - 1) - 5z

Question

How can I simplify this?

Answer 1

     4(2z - 1) - 5z

First, use the distributive property by multiplying the 4 by each term inside the parenthesis... 

     (4·2z - 4·1) - 5z

     8z - 4 - 5z

Then add like term, if any... 

     3z - 4

Answer 2

4(2z - 1) - 5z                   Given

4*2z - 4*1 - 5z               Distribute the 4

8z - 4 - 5z                       Simplify (4*2z = 8z, 4*1 = 4)

8z - 5z - 4                       Commutative property of addition

3z - 4                              Simplify (8z - 5z = 3z)