Lời giải:
a. $\frac{-1}{2}-(\frac{3}{7}-\frac{3}{2})=\frac{-1}{2}-\frac{3}{7}+\frac{3}{2}$
$=(\frac{-1}{2}+\frac{3}{2})-\frac{3}{7}=1-\frac{3}{7}=\frac{4}{7}$
b.
$=\frac{6}{2023}(\frac{16}{27}+\frac{3}{27}-\frac{1}{27})$
$=\frac{6}{2023}.\frac{18}{27}=\frac{4}{2023}$
c.
\(=(0,75+0,25+1\frac{2}{3}):\frac{-2}{3}=(1+1\frac{2}{3}).\frac{-3}{2}=\frac{8}{3}.\frac{-3}{2}=-4\)
d.
\(A=\frac{1}{1.3}+\frac{1}{3.5}+....+\frac{1}{99.101}\\ =\frac{1}{2}(\frac{3-1}{1.3}+\frac{5-3}{3.5}+....+\frac{101-99}{99.101})\\ =\frac{1}{2}(1-\frac{1}{3}+\frac{1}{3}-\frac{1}{5}+....+\frac{1}{99}-\frac{1}{101})\\ =\frac{1}{2}(1-\frac{1}{101})=\frac{50}{101}\)
