Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Đặt \(A=\frac54+\frac58+\frac{5}{16}+\frac{5}{32}+\frac{5}{64}\)
=>\(A\times2=\frac52+\frac54+\frac58+\frac{5}{16}+\frac{5}{32}\)
=>\(2\times A-A=\frac52+\frac54+\frac58+\frac{5}{16}+\frac{5}{32}-\frac54-\frac58-\frac{5}{16}-\frac{5}{32}-\frac{5}{64}\)
=>\(A=\frac52-\frac{5}{64}=\frac{160}{64}-\frac{5}{64}=\frac{155}{64}\)
Ta có: \(1+\frac54+\frac58+\frac{5}{16}+\frac{5}{32}+\frac{5}{64}\)
\(=1+\frac{155}{64}=\frac{64+155}{64}=\frac{219}{64}\)
a ) \(\frac{2003\times14+1988+2001+2002}{2002+2002\times503+504\times2002}\)
= \(\frac{\left(2002+1\right)\times14+1988+2001\times2002}{2002\times\left(1+503+504\right)}\)
= \(\frac{2002\times14+14+1998+2001\times2002}{2002\times1008}\)
= \(\frac{2002\times14+2002+2001\times2002}{2002\times1008}\)
= \(\frac{2002\times\left(14+1+2001\right)}{2002\times1008}\)
= \(\frac{2016}{1008}\)
= 2
b ) Đặt A = 1/4 + 1/8 + 1/16 + 1/32 + 1/64 + 1/128
=> 2A = 1/2 + 1/4 + 1/8 + 1/16 + 1/32 + 1/64
=> 2A - A = ( 1/2 + 1/4 + 1/8 + 1/16 + 1/32 + 1/64 ) - ( 1/4 + 1/8 + 1/16 + 1/32 + 1/64 + 1/128 )
=> A = 1/2 - 1/128
A = 63/128
a) \(A=\left(48\cdot0,75-\frac{240}{10}\right)-\left(16\cdot0,5-\frac{16}{4}\right)\)
\(A=48\cdot0,75-24-16\cdot0,5-4\)
\(A=48\cdot0,5\cdot\frac{3}{2}-24-16\cdot0,5+4\)
\(A=72\cdot0,5-16\cdot0,5-24+4\)
\(A=0,5\left(72-16\right)-20\)
\(A=\frac{1}{2}\cdot56-20\)
\(A=28-20=8\)
b) \(B=937,246\cdot6,149+62,754\cdot6,149-6149\)
\(B=937,246\cdot6,149+62,754\cdot6,149-1000\cdot6,149\)
\(B=6,149\left(937,246+62,754-1000\right)\)
\(B=6,149\cdot0=0\)
1/2 + 1/4+ 1/8+ 1/16 + 1/32 + 1/64 + 1/128 + 1/256 + 1/512
= 1 – 1/2 + 1/2- 1/4 + 1/4 – 1/8 + 1/8 – 1/16 + 1/16 – 1/32 + 1/32 – 1/64 + 1/64 – 1/128 + 1/128 – 1/256 – 1/256 – 1/512
= 1 – 1/512
= 511/512
hok tot
85 x 42 + 32 x 8 + 5 x 16
=85 x 42 + 32 x 8 + 5 x 2 x 8
=85 x 42 + (32+10) x 8
=(85+8) x 42
=93 x 42
=3906
chúc bạn học tốt nha
\(85\times42\)\(+32\times8+5\times16\)
=\(3570+256+80\)
=3906
58 x 42 + 32 x 8 + 5 x 16
= 58 x 42 + 2 x 16 x 8 + 5 x 16
= 58 x 21 x 2 + 16 x ( 2 x 8 + 5 )
= 58 x 21 x 2 + 16 x 21
= 21 x ( 58 x 2 + 16 )
= 21 x ( 116 + 16 )
= 21 x 132
= 2772
\(58\times42+32\times8+5\times16\)
\(=16\times16+5\times16+58\times42\)
\(=16\times\left(16+5\right)+58\times42\)
\(=16\times21+58\times42\)
\(=16\times21+116\times21\)
\(=\left(16+116\right)\times21\)
\(=132\times21\)\(=2772\)
960
\(=32+42\cdot16+48\cdot5+16\)
\(=48\cdot6+42\cdot16\)
=288+672
=960
960