Question

rút gọn a)(3x+5)^2+(3x-5)^2-(3x+2)*(3x-2)

             B)(x+2)^3-x(x^2+6x-5)+8

Answer 1

`a, = 9x^2 + 30 x + 25 + 9x^2 - 30x + 25 - 9x^2 + 4`

`= 25 + 25 + 4`

`= 54`.

`b, = x^3 + 6x^2 + 12x + 8 - x^3 - 6x^2 + 5x + 8`

`= 12x + 5x + 8 + 8`

`= 17x + 16`

Answer 2

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

`=9x^2+30x+25+9x^2-30x+25-9x^2+4`

`=9x^2+54`

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

`b)(x+2)^3-x(x^2+6x-5)+8`

`=x^3+6x^2+12x+8-x^3-6x^2+5x+8`

`=17x+16`