giúp  mik với

rut gọn ak

\(\frac{5.18-10.27+15.36}{10.36-20.54+30.72}\)

\(=\frac{5.18-\left(5.2\right).27+\left(5.3\right).36}{\left(5.2\right).36-\left(5.4\right).54+\left(5.6\right).72}\)

\(=\frac{5.18-5.\left(2.27\right)+5.\left(3.36\right)}{5.\left(2.36\right)-5.\left(4.54\right)+5.\left(6.72\right)}\)

\(=\frac{5.18-5.54+5.108}{5.72-5.216+5.432}\)

\(=\frac{5.\left(18-54+108\right)}{5.\left(72-216+432\right)}\)

\(=\frac{5.\left(-36+108\right)}{5.\left(-144+432\right)}\)

\(=\frac{5.72}{5.288}\)

\(=\frac{5.72}{5..4.72}\)

\(=\frac{1}{4}\)

\(\frac{5.18-10.27+15.36}{10.36-20.54+30.72}\)

\(=\frac{5.18-10.27+15.36}{5.2.18.2-10.2.27.2+15.2.36.2}\)

\(=\frac{5.18-10.27+15.36}{5.8.2.2-10.27.2.2+15.36.2.2}\)

\(=\frac{1}{2.2-2.2+2.2}\)

\(=\frac{1}{2.2}=\frac{1}{4}\)

Giúp mik với

trước 5h nha

a) \(\frac{120-\left(-0,5\right).\left(-40\right).\left(-5\right).\left(-0,2\right).20.0,25}{5+10+15+...+1995}\)

\(=\frac{120-\left[\left(-0,5\right).\left(-0,2\right)\right].\left[\left(-40\right).0,25\right].\left[\left(-5\right).\left(20\right)\right]}{\left(1995+5\right).\left[\left(1995-5\right)\div5+1\right]\div2}\)

\(=\frac{120-0,1.\left(-10\right).\left(-100\right)}{2000.399\div2}\)

\(=\frac{120-100}{1000.399}\)

\(=\frac{1}{19950}\)

b) \(\frac{5.18-10.27+15.36}{10.36-20.54+30.72}\)

\(=\frac{5.18-2.5.27+3.5.36}{10.2.18-20.2.27+5.2.3.2.36}\)

\(=\frac{5.18-2.5.27+3.5.36}{20.18-20.2.27+20.3.36}\)

\(=\frac{5.\left(18-2.27+3.36\right)}{20.\left(18-2.27+3.36\right)}\)

\(=\frac{1}{4}\)

c) \(\left(\frac{1}{2}-1\right)\left(\frac{1}{3}-1\right)\left(\frac{1}{4}-1\right)...\left(\frac{1}{1999}-1\right)\)

\(=\left(\frac{-1}{2}\right).\left(\frac{-2}{3}\right).\left(\frac{-3}{4}\right)...\left(\frac{-1998}{1999}\right)\)

\(=\frac{\left(-1\right).\left(-2\right).\left(-3\right)...\left(-1998\right)}{2.3.4...1999}\)

\(=\frac{\left(-1\right).\left(-1\right).\left(-1\right)...\left(-1\right)}{1.1.1...1999}\)

Ta có : 1998 số (-1) mà 1998 là số chẵn

Vậy tích của 1998 số (-1) = 1

\(\Rightarrow\frac{\left(-1\right).\left(-1\right).\left(-1\right)...\left(-1\right)}{1.1.1...1999}\)

\(=\frac{1}{1999}\)

mik dg cần gấp

a) \(\frac{-3}{8}\)x \(16\frac{8}{7}\)- 0.375 x \(7\frac{9}{17}\)

=> \(\frac{-3}{8}\)x \(\frac{120}{7}\)- \(\frac{3}{8}\)x \(\frac{128}{17}\)=    \(\frac{-3}{8}\)x   (  \(\frac{120}{7}\)+\(\frac{128}{17}\))

=> =  \(\frac{-3}{8}\)X    \(\frac{2936}{119}\)=\(\frac{-1101}{119}\).   ko thuận tiện đc nữa đâu nha !   tích đi mấy bạn  !

THANKS NHIỀU !

mình làm phần c trước nhé

a)28.13+74.14

=14.26+74.14

=14.(26+74)

=1400

b) 18.123+9.4567.2+3.5310.6

=18.(123+4567+5310)

=18.10000

=180000

c)S=1

~~~~~~~~~~~ai đi ngang qua nhớ để lại k ~~~~~~~~~~~~~

 ~~~~~~~~~~~~ Chúc bạn sớm kiếm được nhiều điểm hỏi đáp ~~~~~~~~~~~~~~~~~~~

~~~~~~~~~~~ Và chúc các bạn trả lời câu hỏi này kiếm được nhiều k hơn ~~~~~~~~~~~~

S = 7256.4375 - 725 / 7255.4375 + 3650

S = ( 7255+1) . 4375 - 725 / 7255.4375 + 3650

S = 7255.4375+4375 - 725 / 7255.4375 +3650

S = 4375 - 725 / 3650

S = 3650 / 3650

S = 1

\(A=\frac{1}{5.9}+\frac{1}{9.13}+\frac{1}{13.17}+........+\frac{1}{100.104}\)

\(=\frac{1}{4}.\left(\frac{4}{5.9}+\frac{4}{9.13}+\frac{4}{13.17}+.......+\frac{4}{100.104}\right)\)

\(=\frac{1}{4}.\left(\frac{1}{5}-\frac{1}{9}+\frac{1}{9}-\frac{1}{13}+.......+\frac{1}{100}-\frac{1}{104}\right)\)

\(=\frac{1}{4}.\left(\frac{1}{5}-\frac{1}{104}\right)\)

\(=\frac{1}{4}.\frac{99}{520}=\frac{99}{2080}\)

= 374 : 187

= 2

k mk nha

374 : ( 17 . 11 )

= 374 : 187

= 2 

......

A)374:(17x11)

=374:187

=2