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Question

If x, y, and z are positive with xy=24, xz = 48, and yz=72, what is the value of x+y+z?

Accepted Answer

Since x=24y=48z we have z = 2y. So 72 = 2y^2, which implies that y=6, x = 4, and z = 12. Hence x+y+z = 22.