a) 5/11 + 4/7 + 6/11 + 10/7 = (5/11 + 6/11) + (4/7 + 10/7)
= 1 + 2 = 3
b) 15/9 + 5/8 - 5/9 + 11/8 = (15/9 - 5/9) + (5/8 + 11/8)
= 10/9 + 2 = 28/9
c) 21/12 + 4/11 + 7/11 - 11/12 = (21/12 - 11/12) + (4/11 + 7/11)
= 10/12 + 1 = 11/6
nhóm từng cai có cùng mẫu số với nhau rồi cộng tử số lại là được
A) \(\frac{5}{11}+\frac{4}{7}+\frac{6}{11}+\frac{10}{7}\)
\(=\left(\frac{5}{11}+\frac{6}{11}\right)+\left(\frac{4}{7}+\frac{10}{7}\right)\)
\(=1+2=3\)
B) \(\frac{15}{9}+\frac{5}{8}-\frac{5}{9}+\frac{11}{8}\)
\(=\left(\frac{5}{8}+\frac{11}{8}\right)+\left(\frac{15}{9}-\frac{5}{9}\right)\)
\(=2+\frac{10}{9}=2\frac{10}{9}\)
C) \(\frac{21}{12}+\frac{4}{11}+\frac{7}{11}-\frac{11}{12}\)
\(=\left(\frac{21}{12}-\frac{11}{12}\right)+\left(\frac{4}{11}+\frac{7}{11}\right)\)
\(=\frac{5}{6}+1=1\frac{5}{6}\)
CHÚC BẠN HỌC TỐT!!
\(a,\frac{5}{11}+\frac{4}{7}+\frac{6}{11}+\frac{10}{7}\)
\(=\left(\frac{5}{11}+\frac{6}{11}\right)+\left(\frac{4}{7}+\frac{10}{7}\right)\)
\(=1+2\)
\(=3\)
\(b,\frac{15}{9}+\frac{5}{8}-\frac{5}{9}+\frac{11}{8}\)
\(=\left(\frac{15}{9}-\frac{5}{9}\right)+\left(\frac{5}{8}+\frac{11}{8}\right)\)
\(=\frac{10}{9}+2\)
\(=\frac{28}{9}\)
