Answer
(a) $(2x+1)\sqrt {3x}$
(b) $2x\sqrt {3x}$
Work Step by Step
(a) $\sqrt {12x^3}+\sqrt {3x}=\sqrt {2^2(3)x^2x}+\sqrt {3x}=2x\sqrt {3x}+\sqrt {3x}=(2x+1)\sqrt {3x}$
(b) $\sqrt {27x^3}-\sqrt {3x^3}=\sqrt {3^2(3)x^2x}-\sqrt {3x^2x}=3x\sqrt {3x}-x\sqrt {3x}=2x\sqrt {3x}$
