Tính
a) \( \displaystyle 5 + {3 \over 5} = \,....\)
b) \(\displaystyle 10 - {9 \over {16}} = \,.....\)
c) \(\displaystyle {2 \over 3} - \left ({1 \over 6} + {1 \over 8}\right) = \,.....\)
a) \(\displaystyle 5 + {3 \over 5} = {5 \over 1} + {3 \over 5} = {{25} \over {5}} + {3 \over 5} = {{28} \over 5}\)
b) \(\displaystyle 10 - {9 \over {16}} = {{10} \over 1} - {9 \over {16}} = {{160} \over {16}} - {9 \over {16}} \displaystyle= {{151} \over {16}}\)
c)
\(\displaystyle \eqalign{ & {2 \over 3} - \left ({1 \over 6} + {1 \over 8}\right) = {2 \over 3} - \left ({4\over 24} + {3 \over 24}\right) \cr & = {2 \over 3} - {7 \over {24}} = {{16} \over {24}} - {7 \over {24}} = {9 \over {24}} = {3 \over 8} \cr} \)
-- Mod Toán lớp 5
Copyright © 2021 HOCTAP247