Which of the following is TRUE for all positive real numbers aaa and bbb?
a+b=a+b\sqrt{a+b} = \sqrt{a} + \sqrt{b}a+b=a+b
a⋅b=ab\sqrt{a} \cdot \sqrt{b} = \sqrt{ab}a⋅b=ab
a1/2+b1/2=(a+b)1/2a^{1/2} + b^{1/2} = (a+b)^{1/2}a1/2+b1/2=(a+b)1/2
ab=ba\frac{\sqrt{a}}{\sqrt{b}} = \sqrt{\frac{b}{a}}ba=ab