Giúp mình với Mình sẽ vote 5 sao

Đáp án: +  Giải thích các bước giải:

 Bài `1:`

`1) (1+3x)^2 = 1+6x+9x^2`

`2) (2a^2+b^2)^2 = 4a^4+4a^2b^2+b^4`

`3) (6-3x)^2= 36-36x+9x^2`

`4) (x/2-2y)^2 =(x^2)/4-2xy+4y^2`

`5) (x+1)^3 =x^3+3x^2+3x+1`

`6) (x-2)^3 =x^3-6x^2+12x+8`

`7) (x+3)^3 =x^3 + 9x^2+27x+27`

`8) (3-1/3 x)^3=27-9x+3x+1/27 x^3`

`9) (3a+1)^3 =27a^3+27a^2+9a+1`

Bài `2:`

`a) 2(x-1)^2-4(x+3)^2+2x(x-5)`

`=2(x^2-2x+1)-4(x^2+6x+9)+2x(x-5)`

`=2x^2-4x+2-4x^2-24x-36+2x^2-10x`

`=-38x-34`

`b) (x-1)^3-x(x^2+x+3)+(2x+1)^2`

`=x^3-3x^2+3x-1-x^3-x^2-3x+4x^2+4x+1`

`=4x`

`c) (2x-1)^2-2(x+3)(2x-1)+(x+3)^2`

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

`=(x-4)^2`

`=x^2-8x+16`

`d) (1-3x)(1+3x)+(x+3)^3-(x-1/2)^2`

`=1-9x^2+x^3+9x+27x+27-x^2+x-1/4`

`=x^3-10x^2+37x+111/4`