189-189+243-45=198

duyệt đi

189-189+243-45=198

a) \(\dfrac{17}{8}-2=\dfrac{1}{8}\)

b) \(\dfrac{189}{45}-3=\dfrac{6}{5}\)

c) \(3-\dfrac{5}{7}=\dfrac{16}{7}\)

d) \(5-\dfrac{1515}{1818}=\dfrac{25}{6}\)

189 + 555 + 211 + 45

= (189 + 211) + (555 + 45)

= 400 + 600

= 1000.

(189+211)+(555+45)

=400+600

=10000

1+189+45+67+90=392 nha 

1+189+45+67+90

=190+45+67+90

=235+67+90

=302+90

=392

94−58+189−65+87−45+12

=36+189−65+87−45+12

=225−65+87−45+12

=160+87−45+12

=247−45+12

=202+12

=214

 Hok tốt !

94-58+189-65+87-45+12= 214

150/101 

làm cụ thể được không Yumi

= \(\frac{4}{99}\)

chuẩn 100%

Hội con 🐄 chúc bạn học tốt!!! 

\(\frac{1}{45}+\frac{1}{105}+\frac{1}{189}+\frac{1}{297}=\frac{4}{99}\)

Học tốt !!!

\(\frac29+\frac{2}{45}+\frac{2}{105}+\frac{2}{189}+\cdots+\frac{2}{1725}\)

\(=\frac23\left(\frac13+\frac{1}{15}+\frac{1}{35}+\frac{1}{63}+\cdots+\frac{1}{575}\right)\)

\(=\frac23\times\frac12\times\left(\frac{2}{1\times3}+\frac{2}{3\times5}+\ldots+\frac{2}{23\times25}\right)\)

\(=\frac13\times\left(1-\frac13+\frac13-\frac15+\cdots+\frac{1}{23}-\frac{1}{25}\right)=\frac13\times\left(1-\frac{1}{25}\right)\)

\(=\frac13\times\frac{24}{25}=\frac{8}{25}\)

1000000000000000000000000000000000000000000000000000000000000

=123458939 tick nha  Danh Lê Thành và mọi người