Which equation does not define a function? y2 + x = 6 y + x3 = 3 y − x2 = 4 y3 − x2 = 7

According to statistics a person will devote 32 years to sleeping and watching tv. the number of years sleeping will exceed the number of years watching tv by 18. over a lifetime, how many years will the person spend on each of these activities

Which is the completely factored from of xy^3-x^3y

What is the number 321,000,000 in scientific notation? also what is the number? ?