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DD
6 tháng 10 2021

\(B=\left(2+1\right)\left(2^2+1\right)\left(2^4+1\right)\left(2^8+1\right)\)

\(=\left(2-1\right)\left(2+1\right)\left(2^2+1\right)\left(2^4+1\right)\left(2^8+1\right)\)

\(=\left(2^2-1\right)\left(2^2+1\right)\left(2^4+1\right)\left(2^8+1\right)\)

\(=\left(2^4-1\right)\left(2^4+1\right)\left(2^8+1\right)\)

\(=\left(2^8-1\right)\left(2^8+1\right)\)

\(=2^{16}-1\)

26 tháng 6 2018

Giải:

a) \(M=\left(2^2+1\right)\left(2^4+1\right)\left(2^8+1\right)\left(2^{16}+1\right)\)

\(\Leftrightarrow3M=3\left(2^2+1\right)\left(2^4+1\right)\left(2^8+1\right)\left(2^{16}+1\right)\)

\(\Leftrightarrow3M=\left(2^2-1\right)\left(2^2+1\right)\left(2^4+1\right)\left(2^8+1\right)\left(2^{16}+1\right)\)

\(\Leftrightarrow3M=\left(2^4-1\right)\left(2^4+1\right)\left(2^8+1\right)\left(2^{16}+1\right)\)

\(\Leftrightarrow3M=\left(2^8-1\right)\left(2^8+1\right)\left(2^{16}+1\right)\)

\(\Leftrightarrow3M=\left(2^{16}-1\right)\left(2^{16}+1\right)\)

\(\Leftrightarrow3M=2^{32}-1\)

\(\Leftrightarrow M=\dfrac{2^{32}-1}{3}\)

Vậy ...

b) \(N=16\left(7^2+1\right)\left(7^4+1\right)\left(7^8+1\right)\left(7^{16}+1\right)\)

\(\Leftrightarrow3N=48\left(7^2+1\right)\left(7^4+1\right)\left(7^8+1\right)\left(7^{16}+1\right)\)

\(\Leftrightarrow3N=\left(7^2-1\right)\left(7^2+1\right)\left(7^4+1\right)\left(7^8+1\right)\left(7^{16}+1\right)\)

\(\Leftrightarrow3N=\left(7^4-1\right)\left(7^4+1\right)\left(7^8+1\right)\left(7^{16}+1\right)\)

\(\Leftrightarrow3N=\left(7^8-1\right)\left(7^8+1\right)\left(7^{16}+1\right)\)

\(\Leftrightarrow3N=\left(7^{16}-1\right)\left(7^{16}+1\right)\)

\(\Leftrightarrow3N=7^{32}-1\)

\(\Leftrightarrow N=\dfrac{7^{32}-1}{3}\)

Vậy ...

8 tháng 6 2016

B=3(2+1)(24+1)(28+1)(216+1)

=(4-1)(22+1)(24+1)(28+1)(216+1)

=[(22-1)(22+1)](24+1)(28+1)(216+1)

=(24-1)(24+1)(28+1)(216+1)

=(28-1)(28+1)(216+1)

=(216-1)(216+1)

=232-1

9 tháng 6 2016

B=3(2+1)(24+1)(28+1)(216+1)

=(4-1)(22+1)(24+1)(28+1)(216+1)

=[(22-1)(22+1)](24+1)(28+1)(216+1)

=(24-1)(24+1)(28+1)(216+1)

=(28-1)(28+1)(216+1)

=(216-1)(216+1)

=232-1

1 tháng 9 2018

đặt biểu thức \(\left(4^2+1\right)\left(4^4+1\right)\left(4^8+1\right)\left(4^{16}+1\right)\) là A

Ta có:\(A=\left(4^2+1\right)\left(4^4+1\right)\left(4^8+1\right)\left(4^{16}+1\right)\)

\(\Rightarrow15.A=\left(4^2-1\right)\left(4^2+1\right)\left(4^4+1\right)\left(4^8+1\right)\left(4^{16}+1\right)\)

\(\Rightarrow15.A=\left(4^4-1\right)\left(4^4+1\right)\left(4^8+1\right)\left(4^{16}+1\right)\)

\(\Rightarrow15.A=\left(4^8-1\right)\left(4^8+1\right)\left(4^{16}+1\right)\)

\(\Rightarrow15.A=\left(4^{16}-1\right)\left(4^{16}+1\right)\)

\(\Rightarrow15.A=4^{32}-1\)

\(\Rightarrow A=\dfrac{4^{32}-1}{15}\)

Vậy giá trị biểu thức trên là \(\dfrac{4^{32}-1}{15}\)

\(b,40^2-39^2+38^2-37^2+...+2^2-1^2\)

\(=\left(40^2-39^2\right)+\left(38^2-37^2\right)+...+\left(2^2-1^2\right)\)

\(=\left(40-39\right)\left(40+39\right)+\left(38-37\right)\left(38+37\right)+...+\left(2-1\right)\left(2+1\right)\)

\(=1+2+...+38+39+40\)

\(=\dfrac{\left(40+1\right).40}{2}=\dfrac{41.40}{2}=820\)

17 tháng 9 2018

A = 12 – 22 + 32 – 42 + … – 20042 + 20052

     A = 1 + (32 – 22) + (52 – 42)+ …+ ( 20052 – 20042)

     A = 1 + (3 + 2)(3 – 2) + (5 + 4 )(5 – 4) + … + (2005 + 2004)(2005 – 2004)

     A = 1 + 2 + 3 + 4 + 5 + … + 2004 + 2005

     A = ( 1 + 2002 ). 2005 : 2 = 2011015

b/  B = (2 + 1)(22 +1)(24 + 1)(28 + 1)(216 + 1)(232 + 1) – 264

     B = (22  - 1) (22 +1)(24 + 1)(28 + 1)(216 + 1)(232 + 1) – 264

     B = ( 24 – 1)(24 + 1)(28 + 1)(216 + 1)(232 + 1) – 264

     B = …

     B =(232 - 1)(232 + 1) – 264

     B = 264 – 1 – 264

     B = - 1

17 tháng 9 2018

xin lỗi nha chỗ câu a mình lộn

chỗ (1+2002)x2005:2=2011015 là sai nha 

       (1+2005)x2005:2= 2011015 là đúng nha 

7 tháng 10 2017

\(100^2-99^2+98^2-97^2+...+2^2-1\)

\(=\left(100^2-99^2\right)+\left(98^2-97^2\right)+....+\left(2^2-1^2\right)\)

\(=\left(100-99\right)\left(100+99\right)+\left(98-97\right)\left(98+97\right)+....+\left(2-1\right)\left(2+1\right)\)

\(=1.199+1.195+...+1.3\)

\(=199+195+....+3\)

\(=\left[\left(\dfrac{199-3}{4}\right)+1\right]:2.\left(199+3\right)=5050\)

\(\left(3+1\right)\left(3^2+1\right)\left(3^4+1\right)\left(3^8+1\right)\left(3^{16}+1\right)\)

\(=4\left(3^2+1\right)\left(3^4+1\right)\left(3^8+1\right)\left(3^{16}+1\right)\)

\(=\dfrac{\left(3^2-1\right)\left(3^2+1\right)\left(3^4+1\right)\left(3^8+1\right)\left(3^{16}+1\right)}{2}\)

\(=\dfrac{\left(3^4-1\right)\left(3^4+1\right)\left(3^8+1\right)\left(3^{16}+1\right)}{2}\)

\(=\dfrac{\left(3^8-1\right)\left(3^8+1\right)\left(3^{16}+1\right)}{2}\)

\(=\dfrac{\left(3^{16}-1\right)\left(3^{16}+1\right)}{2}\)

\(=\dfrac{3^{32}-1}{2}\)

\(3\left(2^2+1\right)\left(2^4+1\right).....\left(2^{64}+1\right)\)

\(=\left(2^2-1\right)\left(2^2+1\right)\left(2^4+1\right)....\left(2^{64}+1\right)\)

\(=\left(2^4-1\right)\left(2^4+1\right).....\left(2^{64}+1\right)\)

\(=\left(2^8-1\right)......\left(2^{64}+1\right)=2^{128}-1\)

3 tháng 7 2015

tách ít ít ra thôi. để cả cộp thế này k ai làm cho đâu. mệt quá

29 tháng 5 2018

\(A=\left(2^2+4^2+...+100^2\right)-\left(1^2+3^2+...+99^2\right)\)

\(A=2^2-1^2+4^2-3^2+...+100^2-99^2\)

\(A=\left(2-1\right)\left(2+1\right)+\left(4-3\right)\left(4+3\right)+...+\left(100-99\right)\left(100+99\right)\)

\(A=1\left(1+2\right)+1\left(3+4\right)+....+1\left(99+100\right)\)

\(A=1+2+3+4+....+99+100\)

A=5050

\(B=3^8.7^8-\left(21^4-1\right)\left(21^4+1\right)\)

\(B=\left(3.7\right)^8-\left(21^8-1\right)\)

\(B=21^8-21^8+1\)

B=1

mà A=5050

⇒ A>B

3 tháng 9 2019

b) \(B=\left(2+1\right)\left(2^2+1\right)\left(2^4+1\right)\left(2^8+1\right)\left(2^{16}+1\right)\left(2^{32}+1\right)-2^{64}\)

\(=\left(2-1\right)\left(2+1\right)\left(2^2+1\right)\left(2^4+1\right)\left(2^8+1\right)\left(2^{16}+1\right)\left(2^{32}+1\right)-2^{64}\)

\(=\left(2^2-1\right)\left(2^2+1\right)\left(2^4+1\right)\left(2^8+1\right)\left(2^{16}+1\right)\left(2^{32}+1\right)-2^{64}\)

\(=\left(2^4-1\right)\left(2^4+1\right)\left(2^8+1\right)\left(2^{16}+1\right)\left(2^{32}+1\right)-2^{64}\)

\(=\left(2^8-1\right)\left(2^8+1\right)\left(2^{16}+1\right)\left(2^{32}+1\right)-2^{64}\)

\(=\left(2^{16}-1\right)\left(2^{16}+1\right)\left(2^{32}+1\right)-2^{64}\)

\(=\left(2^{32}-1\right)\left(2^{32}+1\right)-2^{64}\)

\(=\left(2^{64}-1\right)-2^{64}\)

\(=-1\)

3 tháng 9 2019

\(\left(1^2-2^2\right)+\left(3^2-4^2\right)+....+\left(99^2-100^2\right)\) 

\(=\left(1-2\right)\left(2+1\right)+\left(3-4\right)\left(4+3\right)+....+\left(99-100\right)\left(100+99\right)\) 

\(=\left(-1\right)\left(1+2+3+....+100\right)=\frac{\left(-1\right)100.99}{2}=-4950\)

4 tháng 7 2018

Mình làm câu c trước để bạn hình dung ra nhé, câu a tương tự:

c) \(7\left(2^3+1\right)\left(2^6+1\right)\left(2^{12}+1\right)\left(2^{24}+1\right)\)

\(=\left(8-1\right)\left(2^3+1\right)\left(2^6+1\right)\left(2^{12}+1\right)\left(2^{24}+1\right)\)

\(=\left[\left(2^3-1\right)\left(2^3+1\right)\right]\left(2^6+1\right)\left(2^{12}+1\right)\left(2^{24}+1\right)\)

\(=\left(2^6-1\right)\left(2^6+1\right)\left(2^{12}+1\right)\left(2^{24}+1\right)\)

\(=\left(2^{12}-1\right)\left(2^{12}+1\right)\left(2^{24}+1\right)\)

\(=\left(2^{12}-1\right)\left(2^{24}+1\right)\)

\(=2^{36}-1\)

b) \(\left(x^2-x+4\right)\left(x^2+x+1\right)\left(x^2-1\right)\)

\(=\left(x^2.x^2.x^2\right).\left(-x+4+x+1+\left(-1\right)\right)\)

\(=x^8.\left(-4\right)\)

4 tháng 7 2018

\(a,\left(2+1\right)\left(2^2+1\right)\left(2^4+1\right)\left(2^8+1\right)\)

\(=\left(2-1\right)\left(2+1\right)\left(2^2+1\right)\left(2^4+1\right)\left(2^8+1\right)\)

\(=\left(2^2-1\right)\left(2^2+1\right)\left(2^4+1\right)\left(2^8+1\right)\)

\(=\left(2^4-1\right)\left(2^4+1\right)\left(2^8+1\right)\)

\(=\left(2^8-1\right)\left(2^8+1\right)\)

\(=2^{16}-1\)