Please help me with this

What is the name used to describe a graph where for some value of x, there exists 2 or more different values of y?

Which expressions are equivalent to k/2 choose 2 answers: a k-2 b 2/k c 1/2k d k/2 e k+k

Suppose that one doll house uses the 1 inch scale, meaning that 1 inch on the doll house corresponds to 1/2 foot for life-sized objects. if the doll house is 108 inches wide, what is the width of the full-sized house that it's modeled after? in inches and feet.