URGENT Which, if any, of the following equations defines y as a function of x?

A y=x^2

B y^2= 4 - x^2

C y = ±√1 − 2x

An animal shelter has 21 puppies. if the puppies are 28% of the total dogs and cat population how many dogs and cats are in the animal shelter

Aswimming pool had 2.5 million liters of water in it. some water evaporated, and then the pool only had 22 million liters of water in it. what percent of the water evaporated?

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