Hi please help 1. what is the rate of change from year 2 to year 7?

2. during which interval is the rate of change the greatest?
A. year 0 to year 2
B. year 2 to year 7
C. year 7 to year 9
D. year 9 to year 13

1. 2. ∠b and ∠y are right angles. 3.? 4.? which two statements are missing in steps 3 and 4? ∠x ≅ ∠c △abc ~ △zyx by the sas similarity theorem. ∠b ≅ ∠y △abc ~ △zyx by the sas similarity theorem. = 2 △abc ~ △zyx by the sss similarity theorem. = 2 △abc ~ △zyx by the sss similarity theorem.