Rút gọn :
A = (x2 - x +1)(x4 - x2 +1)(x8 - x4 +1)(x16 -x8 +1)(x32 -x16 +1)
Chứng minh đa thức sau không phụ thuộc vào x:
C = (x2 - 1)(x2 + 1)(x4 + 1)(x8 + 1)(x16 + 1)(x32 + 1) - x64
\(C=\left(x^2-1\right)\left(x^2+1\right)\left(x^4+1\right)\left(x^8+1\right)\left(x^{16}+1\right)\left(x^{32}+1\right)-x^{64}\\ =\left(x^4-1\right)\left(x^4+1\right)\left(x^8+1\right)\left(x^{16}+1\right)\left(x^{32}+1\right)-x^{64}\\ =\left(x^8-1\right)\left(x^8+1\right)\left(x^{16}+1\right)\left(x^{32}+1\right)-x^{64}\\ =\left(x^{16}-1\right)\left(x^{16}+1\right)\left(x^{32}+1\right)-x^{64}\\ =\left(x^{32}-1\right)\left(x^{32}+1\right)-x^{64}\\ =\left(x^{64}-1\right)-x^{64}\\ =-1\)
Vậy đa thức ko phụ thuộc vào x
\(C=(x^2-1)(x^2+1)(x^4+1)(x^8+1)(x^{16}+1)(x^{32}+1)-x^{64}\\=(x^4-1)(x^4+1)(x^8+1)(x^{16}+1)(x^{32}+1)-x^{64}\\=(x^8-1)(x^8+1)(x^{16}+1)(x^{32}+1)-x^{64}\\=(x^{16}-1)(x^{16}+1)(x^{32}+1)-x^{64}\\=(x^{32}-1)(x^{32}+1)-x^{64}\\=x^{64}-1-x^{64}\\=-1\)
⇒ Giá trị của C không phụ thuộc vào giá trị của biến
\(C=\left(x^2-1\right)\left(x^2+1\right)\left(x^4+1\right)\left(x^8+1\right)\left(x^{16}+1\right)\left(x^{32}+1\right)-x^{64}\)
\(C=\left(x^4-1\right)\left(x^4+1\right)\left(x^8+1\right)\left(x^{16}+1\right)\left(x^{32}+1\right)-x^{64}\)
\(C=\left(x^8-1\right)\left(x^8+1\right)\left(x^{16}+1\right)\left(x^{32}+1\right)-x^{64}\)
\(C=\left(x^{16}+1\right)\left(x^{16}-1\right)\left(x^{32}+1\right)-x^{64}\)
\(C=\left(x^{32}-1\right)\left(x^{32}+1\right)-x^{64}\)
\(C=x^{64}-1-x^{64}\)
\(C=-1\)
Vậy: ...
Cho 1 1 − x + 1 1 + x + 2 1 + x 2 + 4 1 + x 4 + 8 1 + x 8 = ... 1 − x 16 . Số thích hợp điền vào chỗ trống là?
A. 16
B. 8
C. 4
D. 20
Thực hiện các phép tính sau:
a) y 4 x 2 − 2 xy + 4 x 2 y 2 − 4 xy với x ≠ 0 và y ≠ 2 x ;
b) 1 1 − x + 1 1 + x + 2 1 + x 2 + 4 1 + x 4 + 8 1 + x 8 + 16 1 + x 16 với x ≠ ± 1 .
rút gọn đa thức:
a(x+1)(x-1)
b(x+1)(x-1)(x2+1)
c(x+1)(x-1)(x2+1)(x4+1)-x8
a) \(\left(x+1\right)\left(x-1\right)\)
\(=x^2-1^2\)
\(=x^2-1\)
b) \(\left(x+1\right)\left(x-1\right)\left(x^2+1\right)\)
\(=\left(x^2-1\right)\left(x^2+1\right)\)
\(=\left(x^2\right)^2-1^2\)
\(=x^4-1\)
c) \(\left(x+1\right)\left(x-1\right)\left(x^2+1\right)\left(x^2+1\right)-x^8\)
\(=\left(x^2-1\right)\left(x^2+1\right)\left(x^4+1\right)-x^8\)
\(=\left(x^4-1\right)\left(x^4+1\right)-x^8\)
\(=\left(x^4\right)^2-1-x^8\)
\(=x^8-1-x^8\)
\(=-1\)
rút gọn phân thức
1 . 8x3-125 / 3(x-3)-(x-3)(8-4x)
2 . x4-y4 / y3-x3
3 . x10-x8-x7-x6-x5-x4-x3-x2+1 / x30+x24+x18+x12+x6+1
2: \(=\dfrac{\left(x-y\right)\left(x+y\right)\left(x^2+y^2\right)}{-\left(x-y\right)\left(x^2+xy+y^2\right)}=\dfrac{-\left(x+y\right)\left(x^2+y^2\right)}{x^2+xy+y^2}\)
D = ( x2 + x + 1)( x21 -x+1)( x4 - x2 + 1)( x8 - x4 + 1)
Bạn cần viết đầy đủ đề: Bao gồm yêu cầu đề và công thức toán để được hỗ trợ tốt hơn.
\(D=\left(x^2+x+1\right)\left(x^2-x+1\right)\left(x^4-x^2+1\right)\left(x^8-x^4+1\right)\)
\(=\left[\left(x^2+1\right)^2-x^2\right]\left(x^4-x^2+1\right)\left(x^8-x^4+1\right)\)
\(=\left(x^4+x^2+1\right)\left(x^4-x^2+1\right)\cdot\left(x^8-x^4+1\right)\)
\(=\left(x^8+2x^4+1-x^4\right)\left(x^8-x^4+1\right)\)
\(=\left(x^8+1\right)^2-x^8\)
\(=x^{16}+x^8+1\)
Rút gọn phân thức: Q = x 10 - x 8 - x 7 + x 6 + x 5 + x 4 - x 3 - x 2 + 1 x 30 + x 24 + x 18 + x 12 + x 6 + 1
Rút gọn biểu thức A = 1 1 - x + 1 1 + x + 2 1 + x 2 + 4 1 + x 4 + 8 1 + x 8
Rút gọn biểu thức:
x(x + y)(x2+y2)(x4+y4)(x8+y8)(x - y) + xy16
\(x\left(x+y\right)\left(x^2+y^2\right)\left(x^4+y^4\right)\left(x^8+y^8\right)\left(x-y\right)+xy^{16}\\ =x\left(x+y\right)\left(x-y\right)\left(x^2+y^2\right)\left(x^4+y^4\right)\left(x^8+y^8\right)+xy^{16}\\ =x\left(x^2-y^2\right)\left(x^2+y^2\right)\left(x^4+y^4\right)\left(x^8+y^8\right)+xy^{16}\\ =x\left(x^4-y^4\right)\left(x^4+y^4\right)\left(x^8+y^8\right)+xy^{16}\\ =x\left(x^8-y^8\right)\left(x^8+y^8\right)+xy^{16}\\ =x\left(x^{16}-y^{16}\right)+xy^{16}\\ =x^{17}-xy^{16}+xy^{16}\\ =x^{17}\)
\(x\left(x+y\right)\left(x^2+y^2\right)\left(x^4+y^4\right)\left(x^8+y^8\right)\left(x-y\right)+xy^{16}\)
\(=x\left(x-y\right)\left(x+y\right)\left(x^2+y^2\right)\left(x^4+y^4\right)\left(x^8+y^8\right)+xy^{16}\)
\(=x\left(x^2-y^2\right)\left(x^2+y^2\right)\left(x^4+y^4\right)\left(x^8+y^8\right)+xy^{16}\)
\(=x\left(x^4-y^4\right)\left(x^4+y^4\right)\left(x^8+y^8\right)+xy^{16}\)
\(=x\left(x^8-y^8\right)\left(x^8+y^8\right)+xy^{16}\)
\(=x\left(x^{16}-y^{16}\right)+xy^{16}\)
\(=x^{17}-xy^{16}+xy^{16}\)
\(=x^{17}\)
\(x(x+y)(x^2+y^2)(x^4+y^4)(x^8+y^8)(x-y)+xy^{16}\\=x(x-y)(x+y)(x^2+y^2)(x^4+y^4)(x^8+y^8)+xy^{16}\\=x(x^2-y^2)(x^2+y^2)(x^4+y^4)(x^8+y^8)+xy^{16}\\=x(x^4-y^4)(x^4+y^4)(x^8+y^8)+xy^{16}\\=x(x^8-y^8)(x^8+y^8)+xy^{16}\\=x(x^{16}-y^{16})+xy^{16}\\=x^{17}-xy^{16}+xy^{16}\\=x^{17}\\Toru\)
Phân tích đa thức thành nhân tử:
a) x4+4 b) x8+x7+1
c) x8+x4+1 d) x5+x+1
e) x2+2x2-24 f) a4+4b4
a: \(x^4+4=\left(x^2-2x+2\right)\left(x^2+2x+2\right)\)
b: \(x^8+x^7+1\)
\(=x^8+x^7+x^6-x^6-x^5-x^4+x^5+x^4+x^3-x^3-x^2-x+x^2+x+1\)
\(=\left(x^2+x+1\right)\left(x^6-x^4+x^3-x+1\right)\)
c: \(x^8+x^4+1\)
\(=\left(x^8+2x^4+1\right)-x^4\)
\(=\left(x^4-x^2+1\right)\cdot\left(x^4+x^2+1\right)\)
\(=\left(x^4-x^2+1\right)\left(x^2+1-x\right)\left(x^2+1+x\right)\)
a)\(x^4+4\\ =\left(x^2\right)^2+4x^2+4-4x^2\\ =\left[\left(x^2\right)^2+4x^2+4\right]-\left(2x\right)^2\\ =\left(x^2+2\right)^2-\left(2x\right)^2\\ =\left(x^2+2+2x\right)\left(x^2+2-2x\right)\)
\(a)\; x^4+4 \\= x^4+4x^2+4-4x^2\\=(x^2+2)^2-4x^2\\=(x^2+2-2x)(x^2+2+2x)\)