Answer:
D
Step-by-step explanation:
With only 4 options, I substituted the possible numbers for Y. When substituting Y for 8, the right hand column wrote:
8 - Z = 4
Another way to think of this is 8 - 4 = 4.
When using 8, Z must equal 4.
Take this information to the left hand column.
8 - Z = Z
We know Z equals 4 so plug this information in. Is it correct?
8 - 4 = 4
This is correct.
Therefore, the answer is 8, or D.
