Toán a)x^2-3x+xy-3y b)ax+2y+2x+ay c)x^2+xy-7x-7y d)x^2-xy-2x+2y e)5x-5y-ax+ay 21/07/2021 By Eden a)x^2-3x+xy-3y b)ax+2y+2x+ay c)x^2+xy-7x-7y d)x^2-xy-2x+2y e)5x-5y-ax+ay
Đáp án: a, x² – 3x + xy – 3y = x(x – 3) + y(x – 3) = (x – 3)(x + y) b, ax + 2y + 2x + ay = ax + 2x + ay + 2y = x(a + 2) + y(a + 2) = (a + 2)(x + y) c, x² +xy – 7x – 7y = x(x + y) – 7(x + y) = (x + y)(x – 7) d, x² – xy – 2x + 2y = x(x – y) – 2(x – y) = (x – y)(x – 2) e, 5x – 5y – ax + ay = 5(x – y) – a(x – y) = (x – y )(5 – a) Trả lời
Đáp án: a, `x^2 – 3x + xy – 3y` `= (x^2 + xy) – (3x + 3y)` `= x(x + y) – 3(x + y)` `= (x – 3)(x + y)` b, `ax + 2y + 2x + ay` `= (ax + ay) + (2y + 2x)` `= a(x + y) + 2(y + x)` `= (a + 2)(x + y)` c, `x^2 + xy – 7x – 7y` `= (x^2 + xy) – (7x + 7y)` `= x(x + y) – 7(x + y)` `= (x – 7)(x + y)` d, `x^2 – xy – 2x + 2y` `= (x^2 – xy) – (2x – 2y)` `= x(x – y) – 2(x – y)` `= (x – 2)(x – y)` e, `5x – 5y – ax + ay` `= (5x – 5y) – (ax – ay)` `= 5(x – y) – a(x – y)` `= (5 – a)(x – y)` Giải thích các bước giải: Trả lời