Given matrix y = [4,8,-3,-6] and matrix z = [-1,-2,7,2]. what is matrix x if 1/2(x+z)=y?

This is so hard and it’s for a test

Yo need asap pls ! markin da brainiest too !

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.