simplify the following expression(-4z +5z)+4z and list the number properties used.

Question

The exact question is:

 

Simplify the following expression using the number properties. Write the name of the number property you used.

(-4z+5z)+4

Answer 1

(-4z+5z)+4z=z+4z=5z;

-4z+(5z+4z)=-4z+9z=5z;

(-4z+4z)+5z=0+5z=5z;

the associative law allows any grouping in addition. Note that a-b is the same as a+(-b), so subtraction can be converted to addition by adding on a negative quantity instead of subtracting a positive quantity.