Tính nhanh tổng sau :P = 3/2 + 3/8 + 3/32 + 3/128 + 3/512
Tính nhanh tổng sau :
P = 3/2 + 3/8 + 3/32 + 3/128 + 3/512
P= 3/2 + 3/8 + 3/32 + 3/128 + 3/512
= 768/512 + 192/512 + 48/512 + 12/512 + 3/512
=1023/512
1. Tính nhanh tổng sau :
3/2 + 3/4 + 3/8 + 3/16 + 3/32 + 3/64 + 3/128 + 3/256 + 3/512 + 3/1024
\(\frac{3}{2}+\frac{3}{4}+\frac{3}{8}+\frac{3}{16}+\frac{3}{32}+\frac{3}{64}+\frac{3}{128}+\frac{3}{256}+\frac{3}{512}+\frac{3}{1024}\)
=\(3.\left(\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+\frac{1}{16}+\frac{1}{32}+\frac{1}{64}+\frac{1}{128}+\frac{1}{256}+\frac{1}{512}+\frac{1}{1024}\right)\)
=\(3.\left(1-\frac{1}{2}+\frac{1}{2}-\frac{1}{4}+\frac{1}{4}-\frac{1}{8}+\frac{1}{8}-\frac{1}{16}+\frac{1}{16}-\frac{1}{32}+\frac{1}{32}-\frac{1}{64}+\frac{1}{64}-\frac{1}{128}+\frac{1}{128}-\frac{1}{256}+\frac{1}{256}-\frac{1}{512}+\frac{1}{512}-\frac{1}{1024}\right)\)
=\(3.\left(1-\frac{1}{1024}\right)=3.\left(\frac{1024}{1024}-\frac{1}{1024}\right)=3.\frac{1023}{1024}=\frac{3069}{1024}\)
Chúc em học tốt
CON TRƯỚC SAI RUI MK NHẦM
tính nhanh tổng sau3/2+3/4+3/8+3/16+3/32+3/64+3/128+3/256+3/512
GIÚP MÌNH NHÁ
(3/2+3/8) +( 3/4 =3/16) +( 3/32+ 3/128)+(3,64+3,256)+3/512
= 4+6/2+6/16+6/896+3/512
=10/2+13/056+3/512
=23/256+3/512
=26/768
Tính tổng:3/2+3/8+3/32+3/128+3/512. Giải nhanh giùm mình trong trưa nay nha. Mình đang cần gấp lắm.
\(\frac{3}{2}+\frac{3}{8}+\frac{3}{32}+\frac{3}{128}+\frac{3}{512}\)
\(=\left(\frac{12}{8}+\frac{3}{8}\right)+\left(\frac{12}{128}+\frac{3}{128}\right)+\frac{3}{512}\)
\(=\frac{15}{8}+\frac{15}{128}+\frac{3}{512}\)
\(=\frac{240}{128}+\frac{15}{128}+\frac{3}{512}\)
\(=\frac{255}{128}+\frac{3}{512}\)
\(=\frac{1020}{512}+\frac{3}{512}\)
\(=\frac{1023}{512}\)
\(\frac{3}{2}+\frac{3}{8}+\frac{3}{32}+\frac{3}{128}+\frac{3}{512}=\frac{3}{1.2}+\frac{3}{2.4}+\frac{3}{4.8}+\frac{3}{8.16}+\frac{3}{16.32}\)
\(=\frac{3}{1}-\frac{3}{2}+\frac{3}{2}-\frac{3}{4}+\frac{3}{8}-\frac{3}{8}+\frac{3}{16}-\frac{3}{16}+\frac{3}{32}\)
\(=3+\frac{3}{32}=\frac{3.32}{32}+\frac{3}{32}=\frac{96+3}{32}=\frac{99}{32}\)
Tính nhanh 3/2 + 3/8 + 3/32 + 3/128 + 3/512
\(...=\dfrac{3}{2}x\left(1+\dfrac{1}{4}+\dfrac{1}{16}+\dfrac{1}{64}+\dfrac{1}{256}\right)\)
\(=\dfrac{3}{2}x\left(\dfrac{256}{256}+\dfrac{64}{256}+\dfrac{16}{256}+\dfrac{4}{256}+\dfrac{1}{256}\right)\)
\(=\dfrac{3}{2}x\dfrac{341}{256}=\dfrac{1023}{512}\)
tính nhanh :
d= 3/2+3/8+3/32+3/128+3/512
Tính nhanh: 3/2 + 3/8 + 3/32 + 3/128 + 3/512
Giúp mình nha thks
Đặt tổng trên là: \(A\)
\(A=\dfrac{3}{2}+\dfrac{3}{8}+\dfrac{3}{32}+\dfrac{3}{128}+\dfrac{3}{512}\)
\(\Rightarrow A.4=6+\dfrac{3}{2}+\dfrac{3}{8}+\dfrac{3}{32}+\dfrac{3}{128}\)
\(\Rightarrow A.4-A=\left(6+\dfrac{3}{2}+\dfrac{3}{8}+\dfrac{3}{32}+\dfrac{3}{128}\right)-\left(\dfrac{3}{2}+\dfrac{3}{8}+\dfrac{3}{32}+\dfrac{3}{128}+\dfrac{3}{512}\right)\)
\(\Rightarrow A.3=6-\dfrac{3}{512}=\dfrac{3069}{512}\)
\(\Rightarrow A=\dfrac{3069}{512}:3=\dfrac{1023}{512}\)
tính nhanh :
3/2+3/8+3/32+3/128+3/512=?
Đặt A=3/2+3/8+...+3/512
bn tách
3/2=3/2^1
3/8=3/2^3
....
3/512=3/2^9
Rồi nhân nó lên trừ đc bao nhiêu - đi A ban đầu là đc
Tinh nhanh:3/2+3/8+3/32+3/128+3/512
Đặt tổng trên = A
\(A=\frac{3}{2}+\frac{3}{8}+\frac{3}{32}+\frac{3}{128}+\frac{3}{512}\)
\(A.4=6+\frac{3}{2}+\frac{3}{8}+\frac{3}{32}+\frac{3}{128}\)
\(A.4-A=\left(6+\frac{3}{2}+\frac{3}{8}+\frac{3}{32}+\frac{3}{128}\right)-\left(\frac{3}{2}+\frac{3}{8}+\frac{3}{32}+\frac{3}{128}+\frac{3}{512}\right)\)
\(A.3=6-\frac{3}{512}=\frac{3069}{512}\)
\(A=\frac{3069}{512}:3=\frac{1023}{512}\)
Đặt A = 3/2 + 3/8 + ... + 3/512
bn tách
3/2 = 3/2^1
3/8 = 3/2^3
...
3/512 = 3/2^9
Rồi nhân nó lên trừ được bao nhiêu - đi A ban đầu là đc
k nka
lấy 6 đâu ra bạn