Rút gọn (73+ 2)(76+ 4)(712+ 16)(724+ 256)
rút gọn p/s sau:
(3/4 - 3/16 - 3/64 - 3/256) / (1 - 1/4 - 1/16 - 1/64)
Bài 3: Tính bằng cách thuận tiện nhất:
a) 257 x 87 + 13 x 257
b) 712 x 25 + 74 x 712 + 712
c) 25 x 914 x 4
d) 259 x 76 – 16 x 259
a= 257 x (87+23)
=257 x 100
=25700
b=712 x (25+74)+752
=75200
c=94100
Chuẩn luôn rồi
Học tốt
Tìm x, biết:
a) x − 1 4 = 3 2 + 1 3 − 7 6
b) x − 4 3 = 1 6 + 5 3 − 1 2 + 7 12
a) x = 31 12 x = − 25 12
b) x = 13 4 x = − 7 12
12549/724 các bạn rút gọn giùm mình với
1.Rút gọn biểu thức
A=(2+1)(2^2+1)(2^4+1)......(2^256+1)
\(A=\left(2+1\right)\left(2^2+1\right)\left(2^4+1\right)....\left(2^{256}+1\right)\)
\(=\left(2^2-1\right)\left(2^2+1\right)\left(2^4+1\right)...\left(2^{256}+1\right)\)
\(=\left(2^4-1\right)\left(2^4+1\right)...\left(2^{256}+1\right)\)
\(=\left(2^8-1\right)\left(2^8+1\right)....\left(2^{256}+1\right)\)
.........................................................
\(=\left(2^{256}-1\right)\left(2^{256}+1\right)\)
\(=\left[\left(2^{256}\right)^2-1^2\right]\)
\(=2^{512}-1\)
Tìm x biết:
a ) | x | = 1 5 + 3 4 ; b ) | x − 5 | = − − 5 3 + 1 4 ;
c ) x − 1 4 = 3 2 + 1 3 − 7 6 ; d ) x − 4 3 = 1 6 + 5 3 − 1 2 + 7 12 .
a ) x = 19 20 x = 19 20 b ) x = 83 12 x = − 37 12
c ) x = 31 12 x = − 25 12 d ) x = 13 4 x = − 7 12
Rút gọn và so sánh phân số:
222/333 và 131313/151515
16/18 và 72/73
\(\frac{222}{333}=\frac{2\times111}{3\times111}=\frac{2}{3}=\frac{2\times5}{3\times5}=\frac{10}{15}\)
\(\frac{131313}{151515}=\frac{13\times10101}{15\times10101}=\frac{13}{15}\)
Có \(\frac{10}{15}< \frac{13}{15}\)nên \(\frac{222}{333}< \frac{131313}{151515}\).
\(\frac{16}{18}=\frac{18-2}{16}=1-\frac{2}{16}\)
\(\frac{72}{73}=\frac{73-1}{73}=1-\frac{1}{73}>1-\frac{2}{73}>1-\frac{2}{16}\)
Suy ra \(\frac{72}{73}>\frac{16}{18}\).
Bài 1
Thực hiện phép tính
a, [ 461 + ( - 78 ) + 40 ] + ( - 461)
b, [ 53 + ( - 76 ) - [ 76 - (- 53)]
c, - 564 + [ ( - 724 ) + 564 + 224 ]
d, ( - 87 ) + ( - 12 ) - (-487 ) - 512
Bài 2 Tìm x
a, x - ( 26 - 23 ) = 7 - ( 13 - 4)
b, 4 . ( x -10 ) = 44 : 22
c, 2x + 10 = 16
d, 90 - ( 5x + 9 ) : 3 = 27
Rút gọn biểu thức:
A= (2+1)(2^2+1)(2^4+1)...........(2^256+1)+1
Ta có:
\(A=\left(2-1\right)\left(2+1\right)\left(2^2+1\right).....+1\)
\(=\left(2^2-1\right)\left(2^2+1\right)....\left(2^{256}+1\right)\)
\(=\left(2^4-1\right)\left(2^4+1\right)....\left(2^{256}+1\right)\)
\(......\)
\(=\left[\left(2^{256}\right)^2-1\right]+1\)
\(=2^{512}\)