Pls help what’s the answer to this

For what values of the variable x is the expression square root of 7x+14+ square root of 7-x a real number?

Angles r and s are complementary. the measure of angle r is 31 degrees. which equation can be used to find angle s?

Which questions would most a reader identify the author's purpose for writing? check all that apply. what type of text is this? what type of reviews did the book receive? how many copies of the book have been sold? what is the central idea? how does this text make one feel?