Phân tích thành nhân tử a) 5(x + 3y) – 15x(x + 3y); b) 2(x + 1)^2 – y(x + 1); c) xy(x + y)^2 – y(x + y); d) xy(x – y) – 2x + 2y.
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18/05/2024
Phân tích thành nhân tử
a) 5(x + 3y) – 15x(x + 3y);
b) 2(x + 1)2 – y(x + 1);
c) xy(x + y)2 – y(x + y);
d) xy(x – y) – 2x + 2y.
Trả lời
Lời giải
a) Ta có: 5(x + 3y) – 15x(x + 3y)
= (x + 3y)(5 – 15x)
= 5(x + 3y)(1 – 3x).
b) Ta có: 2(x + 1)2 – y(x + 1)
= (x + 1)[2(x + 1) – y]
= (x + 1)(2x + 2 – y).
c) Ta có: xy(x + y)2 – y(x + y)
= y(x + y)[x(x + y) – 1]
= y(x + y)(x2 + xy – 1).
d) Ta có: xy(x – y) – 2x + 2y
= xy(x – y) – 2(x – y)
= (x – y)(xy – 2).
