Đáp án:
`(x+(9+\sqrt41)/2)(x+(9-\sqrt41)/2)`
Giải thích các bước giải:
`x^2+9x+10`
`=x^2+2.x.(9)/2+81/4-41/4`
`=x^2+2.x.(9)/2+(9/2)^2-41/4`
`=(x+9/2)^2-41/4`
`=(x+9/2)^2-((\sqrt{41})/(\sqrt4))^2`
`=(x+9/2)^2-(\sqrt41/2)^2`
`=(x+9/2+\sqrt41/2)(x+9/2-\sqrt41/2)`
`=(x+(9+\sqrt41)/2)(x+(9-\sqrt41)/2)`