[latex]-12\sqrt{3*5*3^2*5}=-12\sqrt{3*5^2*3^2}=-12*5*3\sqrt{3}=-180\sqrt{3}[/latex], or, more simply (but I guess high school demands more than that :)) ), [latex]-12\sqrt{675}[/latex]

Shay1800

You have to FOIL it. So 3x-4=-12 3xsquare root of 45= 3 square root 45 -4xroot 15=-4root 15 and root 15 times root 45=root 675. So your final answer would be -12+3root45+4root15+root675