$\frac{5-3√5}{√5-3}$- $\frac{8}{√5-1}$+ $\frac{1- √5}{ √5}$ 18/07/2021 Bởi Amara $\frac{5-3√5}{√5-3}$- $\frac{8}{√5-1}$+ $\frac{1- √5}{ √5}$
Đáp án: `(5-3\sqrt{5})/(\sqrt{5}-3)-8/(\sqrt{5}-1)+(1-\sqrt{5})/\sqrt{5}` `=(-4\sqrt5-15)/5` Giải thích các bước giải: `(5-3\sqrt{5})/(\sqrt{5}-3)-8/(\sqrt{5}-1)+(1-\sqrt{5})/\sqrt{5}` `=((5-3\sqrt{5})(\sqrt{5}+3))/((\sqrt{5}-3)(\sqrt{5}+3))-(8(\sqrt{5}+1))/((\sqrt{5}-1)(\sqrt{5}+1))+((1-\sqrt{5})\sqrt{5})/(\sqrt{5}\sqrt{5})` `=((5-3\sqrt{5})(\sqrt{5}+3))/((\sqrt{5})^2-3^2)-(8(\sqrt{5}+1))/((\sqrt{5})^2-1)+((1-\sqrt{5})\sqrt{5})/5` `=((5-3\sqrt{5})(\sqrt{5}+3))/(5-9)-(8(\sqrt{5}+1))/(5-1)+((1-\sqrt{5})\sqrt{5})/5` `=-[(5-3\sqrt{5})(\sqrt{5}+3)]/4-(8(\sqrt{5}+1))/4+(\sqrt{5}-5)/5` `=(-5\sqrt{5}-15+15+9\sqrt{5})/4-(8(\sqrt{5}+1))/4+(\sqrt{5}-5)/5` `=(4\sqrt{5})/4-(8(\sqrt{5}+1))/4+(\sqrt{5}-5)/5` `=\sqrt{5}-2\sqrt{5}-2+(\sqrt{5}-5)/5` `=-\sqrt{5}-2+(\sqrt{5}-5)/5` `=(-5\sqrt{5})/5-10/5+(\sqrt{5}-5)/5` `=(-5\sqrt{5}-10+\sqrt{5}-5)/5` `=(-4\sqrt5-15)/5` Bình luận
Đáp án:
`(5-3\sqrt{5})/(\sqrt{5}-3)-8/(\sqrt{5}-1)+(1-\sqrt{5})/\sqrt{5}`
`=(-4\sqrt5-15)/5`
Giải thích các bước giải:
`(5-3\sqrt{5})/(\sqrt{5}-3)-8/(\sqrt{5}-1)+(1-\sqrt{5})/\sqrt{5}`
`=((5-3\sqrt{5})(\sqrt{5}+3))/((\sqrt{5}-3)(\sqrt{5}+3))-(8(\sqrt{5}+1))/((\sqrt{5}-1)(\sqrt{5}+1))+((1-\sqrt{5})\sqrt{5})/(\sqrt{5}\sqrt{5})`
`=((5-3\sqrt{5})(\sqrt{5}+3))/((\sqrt{5})^2-3^2)-(8(\sqrt{5}+1))/((\sqrt{5})^2-1)+((1-\sqrt{5})\sqrt{5})/5`
`=((5-3\sqrt{5})(\sqrt{5}+3))/(5-9)-(8(\sqrt{5}+1))/(5-1)+((1-\sqrt{5})\sqrt{5})/5`
`=-[(5-3\sqrt{5})(\sqrt{5}+3)]/4-(8(\sqrt{5}+1))/4+(\sqrt{5}-5)/5`
`=(-5\sqrt{5}-15+15+9\sqrt{5})/4-(8(\sqrt{5}+1))/4+(\sqrt{5}-5)/5`
`=(4\sqrt{5})/4-(8(\sqrt{5}+1))/4+(\sqrt{5}-5)/5`
`=\sqrt{5}-2\sqrt{5}-2+(\sqrt{5}-5)/5`
`=-\sqrt{5}-2+(\sqrt{5}-5)/5`
`=(-5\sqrt{5})/5-10/5+(\sqrt{5}-5)/5`
`=(-5\sqrt{5}-10+\sqrt{5}-5)/5`
`=(-4\sqrt5-15)/5`