N plus 6.2 is no less than 11

Which expression is equivalent to7_/x^2 ÷ 5_/y^3? assume y# 0

Me. i can't figure out this question. give an explanation too. .

The figure shows triangle def and line segment bc, which is parallel to ef: triangle def has a point b on side de and point c on side df. the line bc is parallel to the line ef. part a: is triangle def similar to triangle dbc? explain using what you know about triangle similarity. part b: which line segment on triangle dbc corresponds to line segment ef? explain your answer. part c: which angle on triangle dbc corresponds to angle f? explain your answer. asap