6x-3x+4-2x= no solutions(need help in it)

Which value of c would make he following expression completely factored? 8x+cy

F(n + 1) = f(n) – 8. if f(1) = 100, what is f(6)?

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.