Pls help need it pls

If f(x)=x+7 and g(x)=1/x what is (fog)(x)

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.

Present age of man is 45 years, 5 years back his age was 4 times age of his son what is present age of his son?