cac bn giup mik cau nay vs bn Phân tích các đa thức sau thành nhân tử

Giải thích các bước giải:

$\\$ `4,  a(x + y) - 4x - 4y`

$\\$ `= a(x + y) - 4(x + y)`

$\\$`= (a - 40)(x + y)`

$\\$ `5, x^2 - xy + x - y`

$\\$ `= x(x - y) + x - y`

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

$\\$ `6, ax - bx + ab - x^2`

$\\$ `=  (ax + ab) - (bx - x^2)`

$\\$ `= a(x + b) - x(b - x)`

$\\$ `= (a - x)(x + b)`

$\\$ `7, xz + yz - 5(x + y)`

$\\$ `= z(x + y) - 5(x + y)`

$\\$ `= (z -5)(x + y)`

$\\$ `8, xy + y - 2x - 2`

$\\$ `= y(x + 1) - 2(x + 1)`

$\\$ `= (y - 2)(x+1)`

$\\$ `9, x^2 + ab + ax + bx`

$\\$ `= x(a + x) + b(a + x)`

$\\$ `= (x + b)(a + x)`

$\\$ `10, a(x - y) + bx - by`

$\\$ `= a(x - y) + b(x -y)`

$\\$ `= (a + b)(x - y)`

$\\$ `11, x^2 - 3x + xy - 3y`

$\\$ `= (x^2 + xy) - (3x + 3y)`

$\\$ `= x(x + y) - 3(x + y)`

$\\$ `= (x - 3)(x + y)`

`color{purple}{@SHIN}`