Question

把根号外的因式移到根号内; (1-x）根号x-1分之1

Answer 1

1/(x-1)>=0
1-x<0
所以原式=-(x-1)√[1/(x-1)]
=-√[(x-1)²*1/(x-1)]
=-√(x-1)

Answer 2

5x²-18=9x
x²-9x/5=18/5
x²-9x/5+81/100=18/5+81/100=441/100
(x-9/10)²=(±21/10)²
x-9/10=±21/10
x=-6/5,x=3

4x²-3x=52
x²-3x/4=13
x²-3x/4+9/64=13+9/64=841/64
(x-3/8)²=(±29/8)²
x-3/8=±29/8
x=-13/4,x=4

5x²=4-2x
x²+2x/5=4/5
x²+2x/5+1/25=4/5+1/25=21/25
(x+1/5)²=(±√21/5)²
x+1/5=±√21/5
x=(1-√21)/5,x=(1+√21)/5