Answer:
y=9
Step-by-step explanation:
Because there are 5 y values in the model, you first do:
66-21 = 45
Then, you divide 45 by 5 to get the answer of 9
45/5 = 9
9
66-21=45
45/5 since there is 5 boxes with y which equals 9. So y=9
Evidence 9x5=45. Then 45+21=66.
