Đáp án+Giải thích các bước giải:
`h)(x-1)/(sqrty-1)\sqrt{(y-2sqrty+1)^2/(x-1)^4}(x,y ne 1,y>0)`
`=(x-1)/(sqrty-1)*\sqrt{((sqrty-1)^2)^2/((x-1)^2)^2}`
`=(x-1)/(sqrty-1)*|(sqrty-1)^2/(x-1)^2|`
`=(x-1)/(sqrty-1)*(sqrty-1)^2/(x-1)^2`
`=(sqrty-1)/(x-1)`
`i)I4x-sqrt8+sqrt{x^3+2x^2}/sqrt{x+2}(x> - 2)`
`=4x-2sqrt2+sqrt{x^2(x+2)}/sqrt{x+2}`
`=4x-2sqrt2+sqrt{x^2}`
`=4x-2sqrt2+|x|`
`x>=0=>|x|=x`
`=>I=4x-2sqrt2+x=5x-2sqrt2`
`x<=0=>|x|=-x`
`=>I=4x-2sqrt2+(-x)=3x-2sqrt2`
