Làm giup nha mn oiii

Đáp án:

 `a)(x+5)^2+(y+1)^2`.

`b)(x-y)^2+(y+1)^2`.

`c)(z-3)^2+(t+2)^2`.

`d)(2x-z)^2+(z-1)^2.`

Giải thích các bước giải:

 `a)`

`x^2+10x+26+y^2+2y`

`=x^2+5x+5x+25+y^2+y+y+1`

`=x(x+5)+5(x+5)+y(y+1)+(y+1)`

`=(x+5)(x+5)+(y+1)(y+1)`

`=(x+5)^2+(y+1)^2`.

`b)`

`x^2-2xy+2y^2+2y+1`

`=x^2-2xy+y^2+y^2+2y+1`

`=x^2-xy-xy+y^2+y^2+y+y+1`

`=x(x-y)-y(x-y)+y(y+1)+y+1`

`=(x-y)(x-y)+(y+1)(y+1)`

`=(x-y)^2+(y+1)^2`.

`c)`

`z^2-6z+13+t^2+4t`

`=z^2-3z-3z+9+t^2+4t+4`

`=z(z-3)-3(z-3)+t^2+2t+2t+4`

`=(z-3)(z-3)+(t+2)(t+2)`

`=(z-3)^2+(t+2)^2`.

`d)`

`4x^2+2z^2-4xz-2z+1`

`=4x^2-4xz+z^2+z^2-2z+1`

`=4x^2-2xz-2xz+z^2+z^2-z-z+1`

`=(2x-z)^2+(z-1)^2.`

`@nguyen nam500#hoidap247.`