For positive real numbers xxx and yyy, which statement is ALWAYS true?
x+y=x+y\sqrt{x + y} = \sqrt{x} + \sqrt{y}x+y=x+y
xy=x⋅y\sqrt{xy} = \sqrt{x} \cdot \sqrt{y}xy=x⋅y
x1/2+y1/2=(x+y)1/2x^{1/2} + y^{1/2} = (x + y)^{1/2}x1/2+y1/2=(x+y)1/2
x3⋅y3=x+y3\sqrt[3]{x} \cdot \sqrt[3]{y} = \sqrt[3]{x + y}3x⋅3y=3x+y