Please need help on this anyone

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

Abakery recorded the number of muffins and bagels it sold for a seven day period. for the data presented, what does the value of 51 summarize? a) mean of bagels b) mean of muffins c) range of bagels d) range of muffins sample # 1 2 3 4 5 6 7 muffins 61 20 32 58 62 61 56 bagels 34 45 43 42 46 72 75

Iknow its nothing to do with education, but what type of thing should i wrote here? ? : ) its for mcdonald's btw.