Ta có : 50 x 49 + 53 x 50 = 50 x ( 49 + 53 ) = 50 x 102

Vì 50 x 102 > 101 x 50 

Nên B > A

Hay A < B 

Ta có : 

\(A=101\times50\)

\(B=50\times49+53\times50\)

\(B=50\times\left(49+53\right)\)

\(B=50\times102\)

Vì \(101< 102\Rightarrow A< B\)

B) Ta có : \(1-\frac{1998}{1999}=\frac{1}{1999};1-\frac{1999}{2000}=\frac{1}{2000}\)

Vì 1999 < 2000 nên \(\frac{1}{1999}>\frac{1}{2000}\)

Hay \(\frac{1998}{1999}>\frac{1999}{2000}\)

A) Ta có : \(1-\frac{13}{27}=\frac{14}{27};1-\frac{27}{41}=\frac{14}{41}\)

Vì 27 < 41 nên \(\frac{1}{27}>\frac{1}{41}\)

Hay \(\frac{13}{27}>\frac{27}{41}\)

a) \(x+\frac{1}{6}=-\frac{3}{8}\)

\(x=-\frac{3}{8}-\frac{1}{6}\)

\(x=-\frac{13}{24}\)

~ Thiên mã ~

b) \(\frac{1}{2}.x+\frac{1}{8}.x=\frac{3}{4}\)

\(x.\left(\frac{1}{2}+\frac{1}{8}\right)=\frac{3}{4}\)

\(\frac{5}{8}.x=\frac{3}{4}\)

\(x=\frac{6}{5}\)

~ Thiên Mã ~

\(\left(\frac{1}{4}\times y-\frac{1}{8}\right)\times\frac{3}{4}=\frac{1}{8}\)

\(\frac{1}{4}\times y-\frac{1}{8}=\frac{1}{8}:\frac{3}{4}\)

\(\frac{1}{4}\times y-\frac{1}{8}=\frac{1}{6}\)

\(\frac{1}{4}\times y=\frac{1}{6}+\frac{1}{8}\)

\(\frac{1}{4}\times y=\frac{7}{24}\)

\(y=\frac{7}{24}:\frac{1}{4}\)

\(y=\frac{7}{6}\)

~ Thiên Mã ~

\(-1\frac{5}{7}.15+\frac{2}{7}.\left(-15\right)+\left(-105\right).\left(\frac{2}{7}-\frac{4}{5}+\frac{1}{7}\right)\)

\(=\frac{-12}{7}.15+\frac{2}{7}.\left(-15\right)+\left(-105\right).\left(\frac{-13}{35}\right)\)

\(=\left(\frac{-12}{7}+\frac{-2}{7}\right).15+39\)

\(=\left(-2\right).15+39\)

\(=\left(-30\right)+39\)

\(=9\)

\(3\frac{1}{3}x+16\frac{3}{4}=-19\frac{1}{4}\)

\(\frac{10}{3}x+\frac{67}{4}=\frac{-77}{4}\)

\(\frac{10}{3}x=\frac{-77}{4}-\frac{67}{4}\)

\(\frac{10}{3}x=-36\)

\(x=\left(-36\right):\frac{10}{3}\)

\(x=\frac{-54}{5}\)

\(3\frac{1}{3}x+16\frac{3}{4}=-19\frac{1}{4}\)

\(\Rightarrow\)\(\frac{10}{3}x+\frac{67}{4}=-\frac{77}{4}\)

\(\Rightarrow\)\(\frac{10}{3}x=-\frac{77}{4}-\frac{67}{4}\)

\(\Rightarrow\)\(\frac{10}{3}x=-36\)

\(\Rightarrow\)\(x=-36\times\frac{3}{10}\)

\(\Rightarrow\)\(x=-\frac{54}{5}\)

\(x:4\frac{1}{3}=-2,5\)

\(x:\frac{13}{3}=\frac{-5}{2}\)

\(x=\frac{-5}{2}.\frac{13}{3}\)

\(x=\frac{-65}{6}\)

Hình như đề thiếu ý bn ak ! Bn xem lại đề xg mik làm cho