Tính:
a) \(\displaystyle{4 \over 5} + {2 \over 3}\) b) \(\displaystyle{5 \over {11}} + {4 \over 3}\)
c) \(\displaystyle{3 \over 2} + {5 \over 7}\) d) \(\displaystyle{6 \over {13}} + {5 \over 2}\)
a) \(\displaystyle{4 \over 5} + {2 \over 3} = {{12} \over {15}} + {{10} \over {15}} = {{22} \over {15}}\)
b) \(\displaystyle{5 \over {11}} + {4 \over 3} = {{15} \over {33}} + {{44} \over {33}} = {{59} \over {33}}\)
c) \(\displaystyle{3 \over 2} + {5 \over 7} = {{21} \over {14}} + {{10} \over {14}} = {{31} \over {14}}\)
d) \(\displaystyle{6 \over {13}} + {5 \over 2} = {{12} \over {26}} + {{65} \over {26}} = {{77} \over {26}}\)
-- Mod Toán lớp 4