thu gọn:
a) (2+1)(2^2+1)(2^4+1)..............(2^32+1)-2^64
b) (5+3)(5^2+3^2)(5^4+3^4)...................(5^64+3^64).\(\frac{5^{128}-3^{128}}{2}\)
tính nhanh p/s 1+ 5/4 + 5/8 + 5/16 + 5/32 + 5/64
b) 1/3 +1/9 + 1/27 + 1/81 +...........+ 1/59049
c) 3/2 + 3/8 + 3/32 +3/128 + 3/512
d) 1/2 + 1/4 + 1/8 + 1/16 + 1/32 + 1/64 + 1/128 + 1/256 giúp mình với
b: A=1/3+1/9+...+1/3^10
=>3A=1+1/3+...+1/3^9
=>A*2=1-1/3^10=(3^10-1)/3^10
=>A=(3^10-1)/(2*3^10)
c: C=3/2+3/8+3/32+3/128+3/512
=>4C=6+3/2+...+3/128
=>3C=6-3/512
=>C=1023/512
d: A=1/2+...+1/256
=>2A=1+1/2+...+1/128
=>A=1-1/256=255/256
Thu gọn a):\(\left(2+1\right)\left(2^2+1\right)\left(2^4+1\right).....\left(2^{32}+1\right)-2^{64}\)
b)\(\left(5+3\right)\left(5^2+3^2\right)\left(5^4+3^4\right)...\left(5^{64}+3^{64}\right)+\frac{5^{128}-3^{128}}{2}\)
các pn júp mk nha, mk tik cho, mk cần ngày mai nộp roài
a) (2+1)(2^2+1)(2^4+1)...(2^32+1)-2^64
=(2+1)(2-1)(2^2+1)(2^4+1)...(2^32+1)-2^64
=(2^2-1)(2^2+1)(2^4+1)...(2^32+1)-2^64
=(2^4-1)(2^4+1)....(2^32+1)-2^64
=......
=(2^32-1)(2^32+1)-2^64
=2^64-1-2^64=-1
b)Đặt A=(5+3)(5^2+3^2)(5^4+3^4)...(5^64+3^64)+(5^128-3^128)/2
đặt B=(5+3)(5^2+3^2)(5^4+3^4)...(5^64+3^64)
\(2B=\left(5-3\right)\left(5+3\right)\left(5^2+3^2\right)\left(5^4+3^4\right)...\left(5^{64}+3^{64}\right)\)
\(2B=\left(5^2-3^2\right)\left(5^2+3^2\right)\left(5^4+3^4\right)...\left(5^{64}+3^{64}\right)\)
\(2B=\left(5^4-3^4\right)\left(5^4+3^4\right)...\left(5^{64}+3^{64}\right)\)
\(2B=.......\)
2B=(5^64-3^64)(5^64+3^64)
2B=5^128-3^128
B=(5^128-3^128)/2 (thế vào đề bài)
=> A=B+(5^128-3^128)/2=(5^128-3^128)/2+(5^128-3^128)/2=\(\frac{2\left(5^{128}-3^{128}\right)}{2}=\left(5^{128}-3^{128}\right)\)
a) A = ( 2-1)(2+1)(22+1)...(232+1)-264
=(22-1)(22+1)(24+1)... -264
=....
=264-1-264=1
câu b tương tự nhá
Thu gọn:
a) \(\left(2+1\right)\left(2^2+1\right)\left(2^4+1\right)\times...\times\left(2^{32}+1\right)-2^{64}\)
b) \(\left(5+3\right)\left(5^2+3^2\right)\left(5^4+3^4\right)\times...\times\left(5^{64}+3^{64}\right)+\dfrac{5^{128}-3^{128}}{2}\)
CÁC BẠN GIÚP MIK VS NHÉ !!!!! ĐAG CẦN GẤP
a, \(A=\left(2+1\right)\left(2^2+1\right)\left(2^4+1\right)...\left(2^{32}+1\right)-2^{64}\)
\(=\left(2-1\right)\left(2+1\right)\left(2^2+1\right)\left(2^4+1\right)...\left(2^{32}+1\right)-2^{64}\)
\(=\left(2^2-1\right)\left(2^2+1\right)\left(2^4+1\right)...\left(2^{32}+1\right)-2^{64}\)
\(=\left(2^{32}-1\right)\left(2^{32}+1\right)-2^{64}=2^{64}-1-2^{64}=-1\)
b,\(B=\left(5+3\right)\left(5^2+3^2\right)\left(5^4+3^4\right)...\left(5^{64}+3^{64}\right)+\dfrac{5^{128}-3^{128}}{2}\)
\(=\dfrac{\left(5-3\right)\left(5+3\right)\left(5^2+3^2\right)\left(5^4+3^4\right)...\left(5^{64}+3^{64}\right)}{2}+\dfrac{5^{128}-3^{128}}{2}\)\(=\dfrac{\left(5^2-3^2\right)\left(5^2+3^2\right)\left(5^4+3^4\right)...\left(5^{64}+3^{64}\right)+5^{128}-3^{128}}{2}\)
\(=\dfrac{\left(5^{64}-3^{64}\right)\left(5^{64}+3^{64}\right)+5^{128}-3^{128}}{2}=\dfrac{2.5^{128}}{2}=5^{128}\)
bài 1: thu gọn
a) (2x+1)(22+1)(24+1).....(232+1)-264
b) (5+3)(52+32)(54+34).....(564+364)+\(\dfrac{5^{128^{ }}-3^{128}}{2}\)
bài 2: tính
a) (a-b-2)2-(2a-2b)(a-b-2)+a2+b2-2ab
b) (2+1)(22+1).....(2256+1)-1
c) 24(52+1)(54+1).....(532+1)-564
Giúp Mình Với Nha
Bài 2:
a: \(\left(a-b-2\right)^2-\left(2a-2b\right)\left(a-b-2\right)+a^2-2ab+b^2\)
\(=\left(a-b\right)^2-4\left(a-b\right)+4+\left(a-b\right)^2-2\left(a-b\right)\left(a-b-2\right)\)
\(=2\left(a-b\right)^2-4\left(a-b\right)+4-2\left[\left(a-b\right)^2-2\left(a-b\right)\right]\)
\(=2\left(a-b\right)^2-4\left(a-b\right)+4-2\left(a-b\right)^2+4\left(a-b\right)\)
\(=4\)
b: \(\left(2+1\right)\left(2^2+1\right)\cdot...\cdot\left(2^{256}+1\right)-1\)
\(=\left(2^2-1\right)\left(2^2+1\right)\left(2^4+1\right)\cdot...\cdot\left(2^{256}+1\right)-1\)
\(=\left(2^4-1\right)\left(2^4+1\right)\left(2^8+1\right)\cdot...\cdot\left(2^{256}+1\right)-1\)
\(=\left(2^8-1\right)\left(2^8+1\right)\left(2^{16}+1\right)\cdot...\cdot\left(2^{256}+1\right)-1\)
\(=\left(2^{16}-1\right)\left(2^{16}+1\right)\left(2^{32}+1\right)\cdot...\cdot\left(2^{256}+1\right)-1\)
\(=\left(2^{32}-1\right)\left(2^{32}+1\right)\left(2^{64}+1\right)\cdot...\cdot\left(2^{256}+1\right)-1\)
\(=\left(2^{64}-1\right)\left(2^{64}+1\right)\left(2^{128}+1\right)\left(2^{256}+1\right)-1\)
\(=\left(2^{128}-1\right)\left(2^{128}+1\right)\left(2^{256}+1\right)-1\)
\(=\left(2^{256}-1\right)\left(2^{256}+1\right)+1\)
\(=2^{512}-1+1=2^{512}\)
c: \(24\left(5^2+1\right)\left(5^4+1\right)\cdot...\cdot\left(5^{32}+1\right)-5^{64}\)
\(=\left(5^4-1\right)\left(5^4+1\right)\left(5^8+1\right)\left(5^{16}+1\right)\left(5^{32}+1\right)-5^{64}\)
\(=\left(5^8-1\right)\left(5^8+1\right)\left(5^{16}+1\right)\left(5^{32}+1\right)-5^{64}\)
\(=\left(5^{16}-1\right)\left(5^{16}+1\right)\left(5^{32}+1\right)-5^{64}\)
\(=\left(5^{32}-1\right)\left(5^{32}+1\right)-5^{64}\)
=-1
bài 1: thu gọn
a) (2x+1)(22+1)(24+1).....(232+1)-264
b) (5+3)(52+32)(54+34).....(564+364)+\(\dfrac{5^{128^{ }}-3^{128}}{2}\)
bài 2: tính
a) (a-b-2)2-(2a-2b)(a-b-2)+a2+b2-2ab
b) (2+1)(22+1).....(2256+1)-1
c) 24(52+1)(54+1).....(532+1)-564
Giúp Mình Với Nha
Giúp vs @@Phạm Hoàng GiangTrần Quốc LộcTrần Thị Hươnghattori heijiTRẦN MINH HOÀNGAn Nguyễn BáRibi Nkok NgokKien Nguyen
Sửa đề bài 1 : Rút gọn
a,\(\left(2+1\right)\left(2^2+1\right)\left(2^4+1\right).........\left(2^{32}+1\right)-2^{64}\)
Bài 2:
a) \(\left(a-b-2\right)^2-\left(2a-2b\right)\left(a-b-2\right)+a^2+b^2-2ab\)
\(=\left(a-b-2\right)^2-2\left(a-b\right)\left(a-b-2\right)+\left(a-b\right)^2\)
\(=\left[\left(a-b-2\right)-\left(a-b\right)\right]^2\)
\(=\left(a-b-2-a+b\right)^2\)
\(=\left(-2\right)^2=2^2=4\)
b) \(\left(2+1\right)\left(2^2+1\right)...\left(2^{256}+1\right)-1\)
\(=1\left(2+1\right)\left(2^2+1\right)...\left(2^{256}+1\right)-1\)
\(=\left(2-1\right)\left(2+1\right)\left(2^2+1\right)...\left(2^{256}+1\right)-1\)
\(=\left(2^2-1\right)\left(2^2+1\right)...\left(2^{256}+1\right)-1\)
\(=\left(2^4-1\right)\left(2^4+1\right)...\left(2^{256}+1\right)-1\)
...
\(=\left(2^{256}-1\right)\left(2^{256}+1\right)-1\)
\(=2^{512}-1-1\)
\(=2^{512}-2\)
\(=2\left(2^{511}-1\right)\)
c) \(24\left(5^2+1\right)\left(5^4+1\right)...\left(5^{32}+1\right)-5^{64}\)
\(=\left(5^2-1\right)\left(5^2+1\right)\left(5^4+1\right)...\left(5^{32}+1\right)-5^{64}\)
\(=\left(5^4-1\right)\left(5^4+1\right)...\left(5^{32}+1\right)-5^{64}\)
...
\(=\left(5^{32}-1\right)\left(5^{32}+1\right)-5^{64}\)
\(=5^{64}-1-5^{64}\)
\(=-1\)
Chúc bạn học tốt!
Tính nhanh
A. 1/2 + 1/4 + 1/8 + 1/16 + 1/32 + 1/64 + 1/128
B. 2/1*3 + 2/3*5 + 2/5*7 + 2/7*9 + 2/9*11
Tính giá trị của biểu thức
a, 1/4 + 1/5 + 3/4 + 2/5
b, 2/7 + 5/14 + 1/7 + 3/14
c, ( 1-1/2) x ( 1 - 1/3 ) x ( 1-1/4 ) x ( 1-1/5 )
d, 1/4 + 1/8 + 1/16 + 1/32 + 1/64 + 1/128
C=3/2+3/4+3/8+3/16+...+3/128
D=1/2+1/4+1/8+...+1/1024
E=5/2+5/8+5/32+5/128+5/512+5/2048
tính nhanh
a,1/2+1/4+1/8+1/16+1/32+1/64+1/128+1/256
b,1/1*2+1/2*3+1/3*4+1/5*6+.....+1/9*10