What is 10 plus 5 to the 3 power minus 1? Order of operation

I'll give brainliest if you answer right : )

The suare root of 9x plus 7 plus the square rot of 2x equall to 7

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.