Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
a, \(\frac{16x24x9}{27x6}\)= \(\frac{16x4x6x9}{3x9x6}=\frac{64}{3}\)
b, 638 x 14 + 319 x 28
= 2 x 319 x 14 + 319 x 28
= 2 x 319 x ( 14 + 28 )
= 2x 319 x 42
= 26796
Anh ơi, em thấy phần a) anh làm đúng rồi nhưng phần b) hình như sai thì phải
a) \(\frac{8}{11}-\frac{28}{99}-\frac{14}{99}=\frac{72}{99}-\frac{28}{99}-\frac{14}{99}=\frac{30}{99}=\frac{10}{33}\)
b) \(5\frac{3}{4}-3\frac{1}{2}=\)\(\frac{23}{4}-\frac{7}{2}=\frac{23}{4}-\frac{14}{4}=\frac{9}{4}\)
A) 8/11- 28/99- 14/99 8/11=72/99 (72/99 +28/99)-14/99 =100/99-14/99 =86/99
\(\frac{1\cdot3\cdot5+2\cdot6\cdot10+3\cdot9\cdot15}{3\cdot5\cdot12+6\cdot10\cdot24+9\cdot15\cdot36}=\frac{1+1+1}{12+12+12}=\frac{3\cdot1}{3\cdot12}=\frac{1}{12}\)
a) 11x2x17x4x21/11x17x63=8/3
b)5x7x13x2/2x7x13x5x5=1/5
Đặt :
\(A=\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+\frac{1}{16}+\frac{1}{32}+\frac{1}{64}+\frac{1}{128}\)
\(\Leftrightarrow\)\(A=\frac{1}{2}+\frac{1}{2^2}+\frac{1}{2^3}+\frac{1}{2^4}+\frac{1}{2^5}+\frac{1}{2^6}+\frac{1}{2^7}\)
\(\Leftrightarrow\)\(2A=1+\frac{1}{2}+\frac{1}{2^2}+\frac{1}{2^3}+\frac{1}{2^4}+\frac{1}{2^5}+\frac{1}{2^6}\)
\(\Leftrightarrow\)\(2A-A=\left(1+\frac{1}{2}+\frac{1}{2^2}+\frac{1}{2^3}+...+\frac{1}{2^6}\right)-\left(\frac{1}{2}+\frac{1}{2^2}+\frac{1}{2^3}+...+\frac{1}{2^7}\right)\)
\(\Leftrightarrow\)\(A=1-\frac{1}{2^7}\)
Vậy \(A=1-\frac{1}{2^7}\)
\(=\left(\frac{3}{5}+\frac{2}{5}\right)+\left(\frac{6}{11}+\frac{16}{11}\right)+\left(\frac{7}{13}+\frac{19}{13}\right)\)
\(=1+2+2\)
\(=5\)
Ta có \(\frac{8}{9}+\frac{14}{27}+\frac{1}{9}=\left(\frac{8}{9}+\frac{1}{9}\right)+\frac{14}{27}=1+\frac{14}{27}=\frac{41}{27}\)
Ta có \(\frac{1}{2}+\frac{3}{4}+\frac{1}{2}=\left(\frac{1}{2}+\frac{1}{2}\right)+\frac{3}{4}=1+\frac{3}{4}=\frac{7}{4}\)
\(\frac{8}{9}+\frac{14}{27}+\frac{1}{9}=\left(\frac{8}{9}+\frac{1}{9}\right)+\frac{14}{27}=1+\frac{14}{27}=\frac{41}{27}\)
\(\frac{1}{2}+\frac{3}{4}+\frac{1}{2}=\left(\frac{1}{2}+\frac{1}{2}\right)+\frac{3}{4}=1+\frac{3}{4}=\frac{7}{4}\)
a) 2/9 +1/5 +7/9+4/5
=( 2/9+7/9)+(1/5+4/5)
=1+1=2
b) 1/12+3/16+5/12+5/16
=(1/12 +5/12)+(3/16+5/16)
=1/2 +1/2=1