Answer:
z = 0
Step-by-step explanation:
3 (z + 7) = 21
3z + 21 = 21
3z = 0
z = 0
Answer: a
Step-by-step explanation:
Yes because 1 1/4 + 1 1/2 = 2 3/4
Answer:

Step-by-step explanation:
We want to find
.
can be written as
, so we can now write our original equation as:
.
We can combine like terms: 
Hope this helps!