Question

Which of the following expressions can be combined?

Answer 1

Answer:  Choice C

Work Shown:

$2\sqrt{12} - 6\sqrt{27}\\\\2\sqrt{4*3} - 6\sqrt{9*3}\\\\2\sqrt{4}*\sqrt{3} - 6\sqrt{9}*\sqrt{3}\\\\2*2*\sqrt{3} - 6*3*\sqrt{3}\\\\4\sqrt{3} - 18\sqrt{3}\\\\(4-18)\sqrt{3}\\\\-14\sqrt{3}$

In short,

$2\sqrt{12} - 6\sqrt{27}=-14\sqrt{3}$