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\(14.\frac{5}{21}=\frac{14}{1}.\frac{5}{21}=\frac{14.5}{21}=\frac{10}{3}\)
\(\frac{5}{21}.14=\frac{5.14}{21.1}=\frac{5.2}{3.1}=\frac{10}{3}\)
\(10:\frac{5}{3}=10.\frac{3}{5}=\frac{10.3}{5}=2.3=6\)
\(\frac{5}{3}:10=\frac{5}{3}.\frac{1}{10}=\frac{5}{3.10}=\frac{1}{6}\)
4/5 x 0,5 + 12/5 x 0,3 + 8 : 10 x 0,2
=4/5 x 0,5 + 12/5 x 0,3 + 4/5 x 0,2
=(4/5 + 12/5 + 4/5) x (0,5 + 0.3 + 0,2)
=4 x 1
=4
\(\frac{4}{5}x0,5+\frac{12}{5}x0,3+8:10x0,2=\)\(\frac{4}{5}x0,5+\frac{12}{5}x0,3+\frac{8}{10}x0,2=\)\(\frac{4}{5}x0,5+\frac{12}{5}x0,3+\frac{4}{5}x0,2=\)
\(=\frac{4}{5}x\left(0,5+0,2\right)+\frac{12}{5}x0,3\)\(=\frac{4}{5}x\frac{7}{10}+\frac{12}{5}x0,3=\frac{32}{25}\)
( 12/26 + 5/8 ) + 7/13
= 12/26 + 5/8 + 7/13
= 5/8 + 12/26 + 7/13
= 5/8 + 12/26 + 14/26
= 5/8 + 1
= 13/8
( \(\frac{12}{26}+\frac{5}{8}\) )+\(\frac{7}{13}\)
= \(\frac{6}{13}+\frac{5}{8}\)+\(\frac{7}{13}\)
=( \(\frac{6}{13}+\frac{7}{13}\))+ \(\frac{5}{8}\)
=1+\(\frac{5}{8}\)
=\(1\frac{5}{8}=\frac{13}{8}\)
1/3xD=1/(2x4)+1/(4x6)+...+1/(98x100)
2/3xD=2/(2x4)+2/(4x6)+...+1/(98x100)
2/3xD= 1/2-1/4+1/4-1/6+...+1/98-1/100
2/3xD=1/2-1/100
2/3xD=49/100
D=147/200
\(\frac{3}{2}+\frac{3}{8}+\frac{3}{32}+\frac{3}{128}+\frac{3}{512}\)
=\(\frac{3}{1.2}+\frac{3}{2.4}+\frac{3}{4.8}+\frac{3}{8.16}+\frac{3}{16.32}\)
=\(\frac{3}{1}-\frac{3}{2}+\frac{3}{2}-\frac{3}{4}+\frac{3}{4}-\frac{3}{8}+\frac{3}{8}-\frac{3}{16}+\frac{3}{16}-\frac{3}{36}\)
=\(\frac{3}{1}-\frac{3}{36}\)=\(\frac{35}{12}\)