Question

tính bằng cách thuận tiện nhất 

a, \(\frac{7}{11}\)+ \(\frac{3}{4}\)+ \(\frac{4}{11}\)+ \(\frac{1}{4}\)                                      b, \(\frac{72}{99}\)- \(\frac{28}{99}\)-- \(\frac{14}{99}\)

Answer 1

A, 7/11+3/4+4/11+1/4=( 7/11 + 4/11 ) + ( 3/4 + 1/4 )

                               =1+1

                                 =2

B, 72/99 - 28/99 - 14/99= 72/99 - ( 28/99 - 14/99 )

                                   = 72/99-14/99

                                   =58/99

Answer 2

A) ( 7/11+4/11)+ ( 3/4+1/4)

=            1        +         1

=                   2

B) (72/99-28/99)-14/99

=            44/99   - 14/99

=                   30/99 =10/33

Answer 3

\(\frac{7}{11}+\frac{3}{4}+\frac{4}{11}+\frac{1}{4}\)

\(=\left(\frac{7}{11}+\frac{4}{11}\right)+\left(\frac{3}{4}+\frac{1}{4}\right)\)

\(=\frac{11}{11}+\frac{4}{4}\)

\(=1+1\)

\(=2\)

b) \(\frac{72}{99}-\frac{28}{99}-\frac{14}{99}=\frac{72-28-14}{99}=\frac{30}{99}=\frac{10}{33}\)

Answer 4

a,\(\frac{7}{11}+\frac{3}{4}+\frac{4}{11}+\frac{1}{4}=\left(\frac{7}{11}+\frac{4}{11}\right)+\left(\frac{3}{4}+\frac{1}{4}\right)=\frac{11}{11}+\frac{4}{4}=1+1=2\)

b,\(\frac{72}{99}-\frac{28}{99}-\frac{14}{99}=\frac{72}{99}-\left(\frac{28}{99}+\frac{14}{99}\right)=\frac{72}{99}-\frac{42}{99}=\frac{30}{99}=\frac{10}{33}\)