1/2+1/4+1/8+1/16+.......+1/124 = ?
Thực hiện phép tính: (Tính nhanh nếu có thể)
1) 347.22 – 22 . ( 216 + 184 ) : 8 ;
2) 132 – [116 – ( 132 – 128 )2] ;
3) 16 :{400 : [200 – ( 37 + 46 . 3 )]} ;
4) {184 : [96 – 124 : 31 ] – 2 }. 3651 ;
5) 46 – [ (16 + 71 . 4 ) : 15 ]} – 2 ;
6) 33.18 + 72 .42 – 41 .18
7)( 56 . 46 – 25 . 23 ) : 23 ;
8) ( 28 . 54 + 56 . 36 ) : 21 : 2 ;
9) ( 76 . 34 – 19 . 64 ) : ( 38 . 9 ) ;
10) ( 2+ 4 + 6 + ….. + 100 ) . ( 36 . 333 – 108 . 111)
11) ( 5 . 411- 3 .165 ): 410
12) \(\dfrac{7256.4375-725}{3650+4375.7255}\)
1/2+1/4+1/8 +.....+1/120+1/124+1/128
Bài 1: tìm x
a) (x+9) + (x-2)+(x+7)+ (x-4)+(x+5) +(x-6)+(x-3)+ (x-8)+(x+1)=95
b) { [( x:2) - ½] :4 - ¼} : 5= 5+ 1/5
Bài 2: tìm X
a) 72 : { 16- [ 47 + ( x-2)]} = 9
b) x + 132 + 128 +124 +... + 76 + 68 = 2016
rút gọn biểu thức
a) A=16^8 -1/(2+1)(2^2+1)(2^4+1)(2^8+1(3^16+1)
b) B=(3+1)(3^2+1)(3^4+1)(3^8+1)(3^16+1)/9^16-1
giúp mk vs ah mk đang cần gấp ah
a) Ta có: \(A=\dfrac{16^8-1}{\left(2+1\right)\left(2^2+1\right)\left(2^4+1\right)\left(2^8+1\right)\left(2^{16}+1\right)}\)
\(=\dfrac{2^{32}-1}{\left(2^2-1\right)\left(2^2+1\right)\left(2^4+1\right)\left(2^8+1\right)\left(2^{16}+1\right)}\)
\(=\dfrac{2^{32}-1}{\left(2^4-1\right)\left(2^4+1\right)\left(2^8+1\right)\left(2^{16}+1\right)}\)
\(=\dfrac{2^{32}-1}{\left(2^8-1\right)\left(2^8+1\right)\left(2^{16}+1\right)}\)
\(=\dfrac{2^{32}-1}{\left(2^{16}-1\right)\left(2^{16}+1\right)}\)
\(=\dfrac{2^{32}-1}{2^{32}-1}=1\)
b) Ta có: \(B=\dfrac{\left(3+1\right)\left(3^2+1\right)\left(3^4+1\right)\left(3^8+1\right)\left(3^{16}+1\right)}{9^{16}-1}\)
\(=\dfrac{\left(3^2-1\right)\cdot\left(3^2+1\right)\left(3^4+1\right)\left(3^8+1\right)\left(3^{16}+1\right)}{2\cdot\left(3^{32}-1\right)}\)
\(=\dfrac{\left(3^4-1\right)\left(3^4+1\right)\left(3^8+1\right)\left(3^{16}+1\right)}{2\cdot\left(3^{32}-1\right)}\)
\(=\dfrac{\left(3^8-1\right)\left(3^8+1\right)\left(3^{16}+1\right)}{2\left(3^{32}-1\right)}\)
\(=\dfrac{\left(3^{16}-1\right)\left(3^{16}+1\right)}{2\left(3^{32}-1\right)}=\dfrac{1}{2}\)
Tính bằng cách thuận tiện nhất: (1+1/2+1/4+1/8+1/16)/(1-1/2+1/4-1/8+1/16)
Bài làm
\(\frac{\left(1+\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+\frac{1}{16}\right)}{\left(1-\frac{1}{2}+\frac{1}{4}-\frac{1}{8}+\frac{1}{16}\right)}\)
\(=\frac{\left(\frac{2}{2}+\frac{1}{2}+\frac{1}{2^2}+\frac{1}{2^3}+\frac{1}{2^4}\right)}{\left(\frac{2}{2}-\frac{1}{2}+\frac{1}{2^2}-\frac{1}{2^3}+\frac{1}{2^4}\right)}\)
\(=\frac{\frac{1}{2}\left(2+1+\frac{1}{2}+\frac{1}{2^2}+\frac{1}{2^3}\right)}{\frac{1}{2}\left(2-1+\frac{1}{2}-\frac{1}{2^2}+\frac{1}{2^3}\right)}\)
\(=\frac{3+\frac{1}{2}+\frac{1}{2^2}+\frac{1}{2^3}}{1+\frac{1}{2}-\frac{1}{2^2}+\frac{1}{2^3}}\)
\(=\frac{\frac{24}{8}+\frac{4}{8}+\frac{2}{8}+\frac{1}{8}}{\frac{8}{8}+\frac{4}{8}-\frac{2}{8}+\frac{1}{8}}\)
\(=\frac{31}{8}\div\frac{11}{8}\)
\(=\frac{31}{8}\cdot\frac{8}{11}\)
\(=\frac{31}{11}\)
P/S: Trông không thuận tiện lắm :/
Hawy tính giúp mình nha mình cho đúng
(1+1/2+1/4+1/8+1/16)/(1-1/2+1/4+1/8+1/16)
tính
\(\frac{\left(1+\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+\frac{1}{16}\right)}{\left(1-\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+\frac{1}{16}\right)}=\frac{\left(\frac{16}{16}+\frac{8}{16}+\frac{4}{16}+\frac{2}{16}+\frac{1}{16}\right)}{\left(\frac{16}{16}-\frac{8}{16}+\frac{4}{16}+\frac{2}{16}+\frac{1}{16}\right)}=\frac{\frac{31}{16}}{\frac{15}{16}}=\frac{31}{16}:\frac{15}{16}=\frac{31}{16}\times\frac{16}{15}=\frac{31}{15}\)
Tính: 1/x-1-1/x+1-2/x^2+1-4/x^4+1-8/x^8+1-16/x^16+1
D = 16^8 - 1 / (2 + 1) (2^2 + 1) (2^4 + 1) (2^8 + 1) (2^16 + 1)
\(\left(2+1\right)\left(2^2+1\right)\left(2^4+1\right)\left(2^8+1\right)\left(2^{16}+1\right)\)
\(=\left(2^2-1\right)\left(2^2+1\right)\left(2^4+1\right)\left(2^8+1\right)\left(2^{16}+1\right)\)
\(=\left(2^4-1\right)\left(2^4+1\right)\left(2^8+1\right)\left(2^{16}+1\right)\)
\(=\left(2^8-1\right)\left(2^8+1\right)\left(2^{16}+1\right)\)
\(=\left(2^{16}-1\right)\left(2^{16}+1\right)\)
\(=2^{32}-1\)
\(=\left(2^4\right)^8-1=16^8-1\)
\(\Rightarrow D=1\)Chúc bạn học tốt.
*) tính tổng
A= 1/x-1 - 1/x+1 - 2/x^2+1 - 4/x^4+1 - 8/x^8+1 - 16/x^16+1
-) 1 phần x-1 trừ đi 1 phần x mũ 2 +1 trừ đi 4 phần x mũ 4 +1 trừ đi 8 phần x mũ 8 + 1 trừ đi 16 phần x mũ 16 +1 ( giải thích cho các ban hiểu ấy mà)