`a)\sqrt{(1/9+1/16).36}`

`=\sqrt{(16/144+9/144).36}`

`=\sqrt{25/144 .36}`

`=5/12 . 6`

`=5/2`

`b)\sqrt{0,01}-\sqrt{0,25}`

`=0,1-0,5`

`=-0,4`

`c)\sqrt{1,44}.\sqrt{0,5625}, 1 2/3`

`=1,2 . 3/4 . 5/3`

`=0,3.5`

`=1,5`

`d)\sqrt{1,96} 2/3 -\sqrt{1,21} 2/3`

`=1,4 . 2/3 -1,1 . 2/3`

`=(1,4-1,1). 2/3`

`=0,3 . 2/3`

`=0,2`

`7-1/2-3/4`

`=28/4-2/4-3/4`

`=23/4`

`(3x+5)(x+1)-(3x-1)(x+1)`

`=(x+1)(3x+5-3x+1)`

`=6(x+1)`

`=6x+6`

`(4x-5)(x+1)-4(x-1)(x+1)=7`

`<=>4x^2 -5x+4x-5-4(x^2-1)=7`

`<=>4x^2 -4x^2 -x-5+4=7`

`<=>-x-1=7`

`<=>-x=7+1`

`<=>-x=8`

`<=>x=-8`

Số lớn là:

`(8+8):2=8`

Số bé là:

`8-8=0`

Vậy hai số cần tìm là `0;8`

`1+1/(1+1/(1+1/3))`

`=1+1/(1+1/(3/3+1/3))`

`=1+1/(1+1/(4/3))`

`=1+1/(1+3/4)`

`=1+1/(4/4+3/4)`

`=1+1/(7/4)`

`=1+4/7`

`=7/7+4/7`

`=11/7`

1.They don't make cars here

`->`Cars weren't made here
2. They feed monkeys at the zoo twice a day

`->`Monkeys are fed at  the zô twice a day

`125^7=(5^3)^7=5^21`

Vì `5^20<5^21`

`=>5^20<125^7`

`1)(x-3)^2=49`

`<=>[(x-3=7),(x-3=-7):}`

`<=>[(x=10),(x=-4):}`

Vậy `S={-4;10}`

`2)4x^2-4x+1=16`

`<=>(2x-1)^2=16`

`<=>[(2x-1=4),(2x-1=-4):}`

`<=>[(2x=5),(2x=-3):}`

`<=>[(x=5/2),(x=-3/2):}`

Vậy `S={-3/2;5/2}`

`3)(3x-1)^3=8`

`<=>3x-1=2`

`<=>3x=1+2=3`

`<=>x=1`

Vậy `S={1}`

`4)(x-21)^3=-27`

`<=>x-21=-3`

`<=>x=-3+21`

`<=>x=18`

Vậy `S={18}`

khôq tin thì lấy Casio tính nè biếc =)