Cho biểu thức P = 5x(3x^2y – 2xy^2 + 1) – 3xy(5x^2 – 3xy) + x^2y^2.
Giải thích
P = 5x(3x2y – 2xy2 + 1) – 3xy(5x2 – 3xy) + x2y2
= 15x3y – 10x2y2 + 5x – 25x3y + 9x2y2 + x2y2
= (15x3y – 25x3y) + (9x2y2 + x2y2 – 10x2y2) + 5x
= – 10x3y + 5x.
P = 5x(3x2y – 2xy2 + 1) – 3xy(5x2 – 3xy) + x2y2
= 15x3y – 10x2y2 + 5x – 25x3y + 9x2y2 + x2y2
= (15x3y – 25x3y) + (9x2y2 + x2y2 – 10x2y2) + 5x
= – 10x3y + 5x.