=x²-(y²-2y+1)=x²-(y-1)²=(x-y+1)(x+y-1)

a) x = 0; 1; 2; 3; 4; 5; 6; 7; 8; 9; 10; 11; 12; 13; 14; 15; 16; 17; 18; 19; 20; 21; 22; 23.

b) x = 0; 2; 3; 4; 5; 6; ;7; 8; 9; 10; 11; 12; 13; 14.

5x²-12x+4=5x²-10x-2x+4

=(5x²-10x)-(2x-4)

=5x(x-2)-2(x-2)

(5x-2)(x-2)

(x-2)(x+3)=x(x+3)+(-2)(x-3)

=x²+3x-2x+6=x²+x+6

y⁴-(y²-1)(y²+1)

=y⁴-y⁴+1

=1

a) 3x (5x²-2x-1)

=15x³-6x²-3x

b) (x²-2xy-3)(-xy)

=-x³y+2x²y²+3xy

c) 1/2x²y(2x³-2/5xy²-1)

=x⁵y-1/5x³y³-1/2x²y

73(g)

chưa đến tết mà chúc sớm quá

\(\frac{1}{1000}+\frac{13}{1000}+\frac{25}{1000}+\frac{37}{1000}+\frac{49}{1000}+...+\frac{87}{1000}+\frac{99}{1000}\)

2,8 tan ?