Question

Bài 1. Tình:
a) sqrt(12, 1 * 100)
b) sqrt 2500 *4,9*0,9
c)sqrt(41 ^ 2 - 40 ^ 2)
d) sqrt 81 6, 25 - 2 ,25 81
e) sqrt(72) * sqrt(50)
f) 1 sqrt(12, 8) * sqrt(0, 2)
g) 6(sqrt(20) + sqrt(45) - sqrt(5)) √5,

h) (sqrt(12) + sqrt(3))(sqrt(27) - sqrt(3))

Answer 1

`sqrt{12,1 . 100}`

`= sqrt{121 . 10}`

`= sqrt{121} . sqrt{10}`

`= 11sqrt{10}`

``

`sqrt{2500 . 4,9 . 0,9}`

`= sqrt{25 . 10 . 10 . 4,9 . 0,9} `

`= sqrt{25 .49 . 9} `

`= sqrt{5^2 .7^2 . 3^2} `

`= 5 . 7 . 3 `

`= 105`

``

`sqrt{41^2 - 40^2}`

`= sqrt{(41+40)(41-40)}`

`= sqrt{81 }`

`= 9`

Answer 2

`sqrt{72} . sqrt{50}`

`= sqrt{36 .2} . sqrt{25.2}`

`= sqrt{6^2 .2} . sqrt{5^2 .2}`

`= 6 sqrt{2} . 5sqrt{2}`

`= 30 . 2 `

`= 60 `

``

`(sqrt{12} + sqrt{3}).(sqrt{27} - sqrt{3})`

`= (2sqrt{3} + sqrt{3}).(3sqrt{3} - sqrt{3})`

`= 3sqrt{3} . 2sqrt{3}`

`= 6 . 3 `

`= 18`