Đáp án+Giải thích các bước giải:
`A1)A=10ax-5ay-2x+y`
`=(10ax-5ay)-(2x-y)`
`=5a(2x-y)-(2x-y)`
`=(2x-y)(5a-1)`
`A2)A=2x^2-6xy+5x-15y`
`=(2x^2-6xy)+(5x-15y)`
`=2x(x-3y)+5(x-3y)`
`=(x-3y)(2x+5)`
`A3)A=ax^2-3axy+bx-3by`
`=(ax^2-3axy)+(bx-3by)`
`=ax(x-3y)+b(x-3y)`
`=(x-3y)(ax+b)`
`A4)A=2ax^3+6ax^2+6ax+18a`
`=2a(x^3+3x^2+3x+9)`
`=2a[(x^3+3x^2)+(3x+9)]`
`=2a[x^2(x+3)+3(x+3)]`
`=2a(x+3)(x^3+3)`
`A5)A=5x^2 y+5xy^2-a^2 x+a^2 y`
`->`Sai đề
Sửa:`A=5x^2 y+5xy^2-a^2 x-a^2 y`
`=(5x^2 y+5xy^2)-(a^2 x+a^2 y)`
`=5xy(x+y)-a^2(x+y)`
`=(x+y)(5xy-a^2)`
`A6)A=10xy^2-5by^2+2a^2 x-aby`
`->`Sai đề
Sửa: `A=10xy^2-5by^2+2ax^2-abx`
`=(10xy^2-5by^2)+(2ax^2-abx)`
`=5y^2(2x-b)+ax(2x-b)`
`=(2x-b)(5y^2+ax)`
