Tính nhanh
C=50^2-49^2+48^2-47^2+...+2^2-1^2
D=(2^2-1)(2^2+1)(2^4+1)(2^8+1)(2^16+1)
E=(3+1)(3^2+1)(3^4+1)(3^8+1)(3^16+1)
Bài 8: Phân tích đa thức sau thành nhân tử
1)(x+y)^2-9x^2
2)(3x-1)^2-16
3)4x^2-(x^2+1)^2
4)(2x+1)^2 -(x-1)^2
5)(x+1)^4 - (x-1)^4
6)25(x-y)^2 - 16(x+y)^2
7) (x^2+xy)^2 - (y^2 + xy)^2
8)(x^2 +4y^2-20)^2 -16(xy-4)^2
Tính nhanh
a) 2.4.(3^2+1)(3^4+1)...(3^16+1)
b) 2.(3+1).(3^2+1)(3^4+1)...(3^16+1)
c) 8.(3^2+1)(3^4+1)...(3^16+1)
bài 6:tính nhanh
7)1\(^2\)-2\(^2\)+3\(^2\)-4\(^2\)+....-2004\(^2\)+2005\(^2\)
8) (2+1)(2\(^2\)+1)(2\(^4\)+1)(2\(^8\)+1)(2\(^{16}\)+1)(2\(^{32}\)+1)-2\(^{64}\)
3(2^2+1)(2^4+1)(2^8+1)(2^16+1)
3(2^2+1)(2^4+1)(2^8+1)(2^16+1) = ?
3(2^2+1)(2^4+1)(2^8+1)(2^16+1)
D = 16^8 - 1 / (2 + 1) (2^2 + 1) (2^4 + 1) (2^8 + 1) (2^16 + 1)
Rút dọn biểu thức
`3(2^2+1)(2^4+1)(2^8+1)(2^(16)+1)`