几道初三的数学题...

9√45/(3√(1/5)*3/2 *√8/3)
=9√45/(9/2*√8/15)
=9*2/9 *√(45*15/8)
=(30√3)/4
=(15√6)/2

√12+1/(2-√3)-|√3-2|+(-1/3)^(-2)
=2√3+2+√3-2+√3+(-3)^2
=4√3+9

3/4*√9x +√x/16 -3x√(1/x)
=9/4*√x+1/4*√x-3√x=-1/2 *√x

(a^2-b^2)/(a^2b-ab^2) ÷(1+(a^2+b^2)/2ab)
=(a+b)(a-b)/ab(a-b)÷[(a+b)^2/2ab]
=2/(a+b)=2/2=1

x^3+3x^2-5x+1
=x^3-1 +3x^2-5x+2
=(x-1)(x^2+x+1)+(3x-2)(x-1)
=(x^2+4x-1)(x-1)
=[(x^4+4x+4)-5)](x-1)
=[(x+2)^2-5](x-1)
=(x+2+√5)(x+2-√5)(x-1)
x=1/(2-√5)=-2-√5
所以原试=0

4/(√5-1)=√5+1
a+b=√5+1
2<√5<3,a=2,b=√5-1
a^2+b^2=4+(√5-1)^2=10-2√5

(2x-1)^2/2=32
2x-1=8或-8 x=9/2或-7/2

(x+1)^2-2(x+1)(2-x)+(2-x)^2=0
[(x+1)-(2-x)]^2=0
(2x-1)^2=0
x1=x2=1/2

y^2-2√2y+2=0
(y-√2)^2=0
y1=y2=√2

x^2-1=3x-3
(x-1)(x+1)=3(x-1)
(x-2)(x-1)=0
x1=2,x2=1

4(y-