`a)F=2/[\sqrt{x}-1]-1/[\sqrt{x}+1]+[2\sqrt{x}]/[x-1]`
`<=>F=[2(\sqrt{x}+1)-(\sqrt{x}-1)+2\sqrt{x}]/[(\sqrt{x}-1)(\sqrt{x}+1)]`
`<=>F=[2\sqrt{x}+2-\sqrt{x}+1+2\sqrt{x}]/[(\sqrt{x}-1)(\sqrt{x}+1)]`
`<=>F=[3\sqrt{x}+3]/[(\sqrt{x}-1)(\sqrt{x}+1)]`
`<=>F=[3(\sqrt{x}+1)]/[(\sqrt{x}-1)(\sqrt{x}+1)]=3/[\sqrt{x}-1]`
__________________________________________________________
`b)G=1/\sqrt{x}-\sqrt{x}/[\sqrt{x}+2]+[2+3\sqrt{x}+2]/[x+2\sqrt{x}]`
`<=>G=[\sqrt{x}+2-x+2x+3\sqrt{x}+2]/[\sqrt{x}(\sqrt{x}+2)]`
`<=>G=[x+4\sqrt{x}+4]/[\sqrt{x}(\sqrt{x}+2)]`
`<=>G=[(\sqrt{x}+2)^2]/[\sqrt{x}(\sqrt{x}+2)]`
`<=>G=[\sqrt{x}+2]/\sqrt{x}`
Đúng 2
Bình luận (0)
