rút gọn biểu thức : (1/cănx – 3 – 1/cănx + 3 ) /3/cănx – 3 14/07/2021 Bởi Gianna rút gọn biểu thức : (1/cănx – 3 – 1/cănx + 3 ) /3/cănx – 3
`(1/(\sqrt{x}-3)-1/(sqrt{x}+3)) : 3/(\sqrt{x}-3)` (ĐKXĐ: `x>=0, x\ne9`) `=(\sqrt{x}+3-\sqrt{x}+3)/((\sqrt{x}-3)(\sqrt{x}+3)). (\sqrt{x}-3)/3` `=6/((\sqrt{x}-3)(\sqrt{x}+3)). (\sqrt{x}-3)/3` `=2/(\sqrt{x}+3)` Bình luận
`(1/(\sqrt{x}-3)-1/(sqrt{x}+3)) : 3/(\sqrt{x}-3)` `\text{(ĐKXĐ: x ≥ 0, x ≠ 9)}` `=(\sqrt{x}+3-\sqrt{x}+3)/((\sqrt{x}-3)(\sqrt{x}+3)). (\sqrt{x}-3)/3` `=6/((\sqrt{x}-3)(\sqrt{x}+3)). (\sqrt{x}-3)/3` `=2/(\sqrt{x}+3)` Bình luận
`(1/(\sqrt{x}-3)-1/(sqrt{x}+3)) : 3/(\sqrt{x}-3)` (ĐKXĐ: `x>=0, x\ne9`)
`=(\sqrt{x}+3-\sqrt{x}+3)/((\sqrt{x}-3)(\sqrt{x}+3)). (\sqrt{x}-3)/3`
`=6/((\sqrt{x}-3)(\sqrt{x}+3)). (\sqrt{x}-3)/3`
`=2/(\sqrt{x}+3)`
`(1/(\sqrt{x}-3)-1/(sqrt{x}+3)) : 3/(\sqrt{x}-3)` `\text{(ĐKXĐ: x ≥ 0, x ≠ 9)}`
`=(\sqrt{x}+3-\sqrt{x}+3)/((\sqrt{x}-3)(\sqrt{x}+3)). (\sqrt{x}-3)/3`
`=6/((\sqrt{x}-3)(\sqrt{x}+3)). (\sqrt{x}-3)/3`
`=2/(\sqrt{x}+3)`