Đáp án+Giải thích các bước giải:
`a.\quad (1-sqrt(x)) (1+sqrt(x)+x)`
`= 1+sqrt(x)+x-sqrt(x)-x-sqrt(x)x`
`= 1-sqrt(x)x`
`b.\quad (sqrt(x)-sqrt(y))(x+y+sqrt(xy))`
`= sqrt(x)x+sqrt(x)y +sqrt(x^2y) -sqrt(y)x -sqrt(y)y -sqrt(xy^2)`
`= sqrt(x)x+sqrt(x)y +xsqrt(y) -sqrt(y)x-sqrt(y)y -ysqrt(x)`
`= sqrt(x)x-sqrt(y)y`
`c.\quad (4sqrt(x)-sqrt(2x))(sqrt(x)-sqrt(2x))`
`= 4x -4sqrt(2x^2) -sqrt(2x^2) +2x`
`= 4x-4sqrt(2)x -sqrt(2)x +2x`
`= 6x -5sqrt(2)x`
`d.\quad (2sqrt(x)-sqrt(y))(3sqrt(x)-2sqrt(y))`
`=6x -4sqrt(xy)-3sqrt(xy) +2y`
`=6x-7sqrt(xy)+2y`
`e.\quad ((xsqrt(y)+ysqrt(x))(sqrt(x)-sqrt(y)))/(sqrt(xy))`
`= (xsqrt(xy)-xy+xy-ysqrt(xy))/sqrt(xy)`
`= (xsqrt(xy)-ysqrt(xy))/(sqrt(xy))`
`= (sqrt(xy)(x-y))/(sqrt(xy))`
`= x-y`
`f.\quad (sqrt(x^3)-1)/(sqrt(x)-1)`
`= (xsqrt(x)-1)/(sqrt(x)-1)`
`= ((sqrt(x)-1)(x+sqrt(x)+1))/(sqrt(x)-1)`
`= x+sqrt(x)+1`