计算或化简

1.原式=[1/3√(3×9)-√(4×6)-3√2/√3]×√12
=(√3-2√6-√6)×√12
=(√3-3√6)×√12
=√3×√12-3√6×√12
=√36-3√72
=6-18√2
2.原式=2/b×√a×b²×√b×(-2/3√a3b÷3√b/a)
=2b√ab×[-2/9×√(a3b×a/b)]
=2b√ab×(-2√3a²/9）
=-4b√3a²b/9
=-4ab√3b/9
3.3(x²-4x+4)=x²-2x
3x²-12x+12=x²-2x
2x²-10x+12=0
x²-5x+6=0
x²-5x+25/4=1/4
(x-5/2)²=1/4
x-5/2=1/2
x=3
4.x²-(5/2)x+1/2=0
x²-(5/2)x+25/16=17/16
(x-5/4)²=17/16
x-5/4=√17/4
x=(5+√17)/4