Please please help me answer a and b

If y varies directly as x2 and y=6 when x=6, find the constant of variation.

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

Abag contains 10 white golf balls and 6 striped golf balls. a golfer wants to add 112 golf balls to the bag. he wants the ratio of white to striped gold balls to remain the same. how many of each should he add?