Đáp án
ĐKXĐ : ` x ge 0`
a) `sqrt{25x}=35`
`<=> 5.sqrt{x}= 35 `
`=> sqrt{x}= 7 `
`=> x = 49`
b) `sqrt{4x} le 162`
`<=> 2 sqrt{x} le 162`
`<=> sqrt{x} = 81`
`=> x = 6561`
c) `3.sqrt{x} = sqrt{12}`
`=> 3.sqrt{x}= 2.sqrt{3}`
`=> (2sqrt{3})/3 = x `
`=> x = 4/3`
d) `2.sqrt{x} ge 10`
`<=> sqrt{x} ge 5`
`=> x ge 25`
