`bb(b o t)`

`bb(4.)` 

`" Đề ko rõ nên thấy chữ giống cái nào thì làm "`

`TH1 : " Với số đẹp thì sửa đề "`

`2sqrt{400} - 2sqrt{100} + sqrt{4^2 . 3^2}`

`= 2sqrt{20^2} - 2sqrt{10^2} + sqrt{(4 . 3)^2}`

`= 2 . 20 - 2 . 10 + sqrt{12^2}`

`= 40 - 20 + 12`

`= 20 + 12`

`= 32`

`TH2: " Theo đề "`

`2sqrt{400} - 2sqrt{100} + sqrt{4^2 . 3^3}`

`= 2sqrt{20^2} - 2sqrt{10^2} + sqrt{(4 . 3)^2 .3}`

`= 2 . 20 - 2 . 10 + sqrt{12^2 . 3}`

`= 40 - 20 + 12sqrt3`

`= 20 + 12sqrt3`

`TH3 : " Theo đề với trường hợp " 3^3 " hoặc "8^3 `

`2sqrt{400} - 2sqrt{100} + sqrt{4^2 . 8^3}`

`= 2sqrt{20^2} - 2sqrt{10^2} + sqrt{2^4 . 2^9}`

`= 2 . 20 - 2 . 10 + sqrt{2^13}`

`= 40 - 20 + 2^6 sqrt2`

`= 20 + 64sqrt2`

`bb(5.)`

`sqrt{64} . 23 + 2sqrt{23^2} - sqrt{144}`

`= sqrt{8^2} . 23 + 2 . 23 - sqrt{12^2}`

`= 8 . 23 + 46 - 12`

`= 184 + 46 - 12`

`= 230 - 12`

`= 218`

`bb(6.)`

`sqrt{0,25} - 3sqrt{0,49} + sqrt{1,44}`

`= sqrt{(0,5)^2} - 3sqrt{(0,7)^2} + sqrt{(1,2)^2}`

`= 0,5 - 3 . 0,7 + 1,2`

`= 0,5 - 2,1 + 1,2`

`= -1,6 + 1,2`

`= -0,4`

`bb(9.)`

`2 . sqrt1/3 + 1/sqrt{25 - 3^2} - (sqrt{1/2})^2`

`= 2 . 1/3 + 1/sqrt{25 - 9} - 1/2`

`= 2/3 + 1/sqrt{16} - 1/2`

`= 2/3 + 1/sqrt{4^2} - 1/2`

`= 2/3 + 1/4 - 1/2`

`= (2 . 4)/12 + (1 . 3)/12 - (1 . 6)/12`

`= 8/12 + 3/12 - 6/12`

`= (8 + 3 - 6)/12`

`= 5/12`

`bb(10.)`

`-sqrt{25} . (-4)/sqrt{225} - 5 . sqrt{121}/15 + (-3)^2`

`= -sqrt{5^2} . (-4)/sqrt{15^2} - 5 . sqrt{11^2}/15 + 9`

`= -5 . (-4)/15 - 5 . 11/15 + 9`

`= 20/15 - 55/15 + 9`

`= (20 - 55)/15 + 9`

`= (-35)/15 + 9`

`= (-7)/3 + 27/3`

`= (-7 + 27)/3`

`= 20/3 .`