Simple explanations please! geometry

Find the number of liters in 12.8 gal of gasoline. round to the nearest hundredths

Find the nonpermissible replacement for binthis expression.b2/5b +5

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.