cái đầu bằng 6888601879216

cái nhì bằng 102437543518

4678×4679+4680×314648=1494441002

4680×4679-4678×4679=9358

\(\frac{4678\times4679+4680\times31+4648}{4680\times4679-4678\times4679}\)

\(\Leftrightarrow\frac{4679\times4678+4679\times31+4679}{4679\times\left(4680-4678\right)}\)

\(=\frac{4679\times\left(4678+31+1\right)}{4679\times2}\)

\(=\frac{4679\times4710}{4679\times2}\)

\(=\frac{4710}{2}\)

\(=2355\)

\(\frac{4678\cdot4679+4680\cdot31+4648}{4680\cdot4679-4678.4679}\)=\(\frac{4678\cdot4679+\left(4680-1\right)\cdot31+4648+31}{4680\cdot4679-4678.4679}\)

=\(\frac{4678\cdot4679+4679\cdot31+4679}{4680\cdot4679-4678.4679}\)=\(\frac{\left(4678+31+1\right)\cdot4679}{\left(4680-4678\right).4679}\)=\(\frac{4710}{2}\)=2355

1,28:0,125+1,28.0,25+1,8.1,75

=1,28.\(\frac{1}{8}\)+1,28.\(\frac{1}{4}\)+1,8.\(\frac{7}{10}\)

=1,28\(\left(\frac{1}{8}+\frac{1}{4}\right)\)+\(\frac{9}{5}\).\(\frac{7}{10}\)

=1,28\(\left(\frac{1}{8}+\frac{2}{8}\right)\)+\(\frac{63}{50}\)

=\(\frac{32}{25}\cdot\frac{3}{8}+\frac{63}{50}\)

\(=\frac{12}{25}\)

sorry vì hơi chậm nha, em tham khảo bài làm của a:

\(1,28\cdot5+1,28:0,25+1,28\)

\(=1,28\cdot5+1,28\cdot4+1,28\)

\(=1,28\left(5+4+1\right)\)

\(=1,25\cdot10=12,5\)

=1,28(16,5+82,5+1)=1,28x100=128

 1,28x16,5+1,28x82,5+1,28

=1,28x(16,5+82,5+1)

=1,28x100

128

 1,28x16,5+1,28x82,5+1,28

=1,28x(16,5+82,5+1)

=1,28x100

=128

Đề bài không rõ ràng nha bạn

Tính A

1,28 thành 2.98

1 A = 1000 mA

1 mA  = 0,001 A

Từ đó em tự tính nhé

\(=\frac{19}{4}+\left(-0.37\right)+\frac{1}{8}+\left(-1.28\right)+\left(-2.5\right)+\frac{37}{12}\)\(\frac{37}{12}\)

\(=\left(\frac{19}{4}+\frac{1}{8}+\frac{37}{12}\right)+\left(\left(-0.37\right)+\left(-1.28\right)+\left(-2.5\right)\right)\)

\(=\frac{191}{24}+\left(-\frac{83}{20}\right)\)

\(=\frac{457}{120}\)

tu giai di ko biet nha!!!!