Xavier is thinking of a number. nine more than four times the number is the same as fifteen less than twice the number. what is xavier's number?

Cone a has a surface area of 384 ft2 and cone b has a surface area of 96 ft? . what is the ratio of their volume?

Math question.. plz me .. best answer all

If (x + 8) is a factor of f(x), which of the following must be true? both x = –8 and x = 8 are roots of f(x). neither x = –8 nor x = 8 is a root of f(x). f(–8) = 0 f(8) = 0