What is 4/5 divided by 7/10

Julius sold five times as many computers as sam sold last year. in total, they sold 78 computers. how many computers did julius sell?

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.

Ntriangle abc, m∠a = 35° and m∠b = 40°, and a=9. which equation should you solve to find b?