\(\frac{25\times8+50\times2+100\times2}{70\times5+105\times2+35\times4}=\frac{50\times4+50\times2+50\times4}{70\times5+70\times3+70\times2}=\frac{50\times\left(4+2+4\right)}{70\times\left(5+3+2\right)}=\frac{50\times10}{70\times10}=\frac{50}{70}=\frac{5}{7}\)

a: =-36-329-71+136-2021

=100-400-2021

=-300-2021

=-2321

a. \(\frac{22}{55}\)+ \(\frac{25}{125}\)+ \(\frac{1020}{5100}\)

= \(\frac{2}{5}\)+ \(\frac{1}{5}\)+ \(\frac{1}{5}\)

= \(\frac{4}{5}\)

B. \(\frac{22}{77}\)+ \(\frac{56}{98}\)+ \(\frac{25}{105}\)

= \(\frac{2}{7}\)+ \(\frac{4}{7}\)+ \(\frac{5}{21}\)

= \(\frac{6}{7}\)+ \(\frac{5}{21}\)

= \(\frac{23}{21}\)

23/21 bn nhé

ai lớp 4 hoặc 5 kb mik nhé mik luôn sẵn sàng

= 23 | 21 nhé bạn

\(\text{25 x 20,23 + 105 x 20,23 - 20,25 x 20,23 - 9,75 x 20,23}\\ =20,23\text{ x }\left(25+105-9,75-20,25\right)\\ =20.23\text{ x }100=2023\)

105² - 25

= 105² - 5²

= (105 - 5).(105 + 5)

= 100.110

= 11000

\(105^2-25\\ =105^2-5^2\\ =\left(105+5\right)\left(105-5\right)\\ =110\cdot100\\ =11000\)

22.23=(20+2).23=460+46=506

44.101=44(100+1)=4400+44=4444

25.105=25(100+5)=250+125=375

 |-105| + |-25| + (-105) + 50

= 105 + 25 + ( - 105) + 50   

= [105 + ( -105)] + ( 25 + 50 ) 

= 0 + 75 = 75