Đáp án:
`f)y^2-x^2+6x-9=(y+x-3)(y-x+3)`
`g)36a^2-10x-25-x^2=(6a+x+5)(6a-x-5)`
Giải thích các bước giải:
`f)y^2-x^2+6x-9`
`=y^2-(x^2-6x+9)`
`=y^2-(x-3)^2`
`=[y+(x-3)][y-(x-3)]`
`=(y+x-3)(y-x+3)`
`g)36a^2-10x-25-x^2`
`=36a^2-(x^2+10x+25)`
`=(6a)^2-(x+5)^2`
`=[6a+(x+5)][6a-(x+5)]`
`=(6a+x+5)(6a-x-5)`