`a)\sqrt{4(x-3)}+\sqrt{9x-27}=10` `ĐK: x >= 3`
`<=>2\sqrt{x-3}+3\sqrt{x-3}=10`
`<=>\sqrt{x-3}=2`
`<=>x-3=4<=>x=7` (t/m).
`b)[\sqrt{x}+8]/[\sqrt{x}-2]=\sqrt{x}+2` `ĐK: x >= 0,x ne 4`
`<=>\sqrt{x}+8=x-4`
`<=>x-\sqrt{x}-12=0`
`<=>(\sqrt{x}-4)(\sqrt{x}+3)=0`
`<=>[(\sqrt{x}=4),(\sqrt{x}=-3(Vô lí)):}<=>x=16` (t/m).
`c)\sqrt{x^2-4x+4}=3x+1` `ĐK: x >= -1/3`
`<=>\sqrt{(x-2)^2}=3x+1`
`<=>|x-2|=3x+1`
`<=>[(x-2=3x+1),(x-2=-3x-1):}`
`<=>[(x=-3/2 (ko t//m)),(x=1/4(t//m)):}`
Đúng 1
Bình luận (0)
