\(M=\frac{5555}{6666}-\frac{246246}{369369}+\frac{222222}{151515}\)

\(M=\frac{5}{6}-\frac{2}{3}+\frac{22}{15}\)

\(M=\frac{49}{30}\)

\(M=\frac{5555}{6666}-\frac{246246}{369369}+\frac{222222}{151515}=\frac{5}{6}-\frac{2}{3}+\frac{22}{15}=\frac{25}{30}-\frac{20}{30}+\frac{44}{30}=\frac{49}{30}\)

\(\frac{5555}{6666}\)=  \(\frac{5}{6}\)

\(\frac{246246}{369369}\)= \(\frac{82}{123}\)

\(\frac{222222}{151515}\)= \(\frac{22}{15}\)

M= \(\frac{5}{6}\)+ \(\frac{82}{123}\)+ \(\frac{22}{15}\)

M= \(\frac{1025}{1230}\)+ \(\frac{820}{1230}\)+ \(\frac{6724}{1230}\)

M= \(\frac{1845}{1230}\)+ \(\frac{6724}{1230}\)

M= \(\frac{8569}{1230}\)

tk nhé

Mình giải thích nhé :\(\frac{5555}{6666}=\frac{5555:1111}{6666:1111}=\frac{5}{6};\frac{246246}{369369}=\frac{246246:123123}{369369:123123}=\frac{2}{3};\frac{222222}{151515}=\frac{222222:10101}{151515:10101}=\frac{22}{15}\)

Đoạn sau là quy đồng phân số rồi cộng lại thôi!

Bài 2: 

\(\Leftrightarrow5a+14\in\left\{2;3;5;7;11;13;17;19;23;29;31;37\right\}\)

\(\Leftrightarrow5a\in\left\{5;15\right\}\)

hay a=3(vì a là số nguyên tố)

\(A=\frac{1}{2}×\frac{3}{4}+\frac{1}{4}×\frac{1}{2}\)

\(A=\frac{1}{2}×\left(\frac{3}{4}+\frac{1}{4}\right)\)

\(A=\frac{1}{2}×\left(\frac{3+1}{4}\right)\)

\(A=\frac{1}{2}×1\)

\(A=\frac{1}{2}\)

\(B=\frac{1212}{2121}×\frac{151515}{161616}\)

\(B=\frac{1212:101}{2121:101}×\frac{151515:10101}{161616:10101}\)

\(B=\frac{12}{21}×\frac{15}{16}\)

\(B=\frac{12×15}{21×16}\)

\(B=\frac{3×4×3×5}{3×7×4×4}\)

\(B=\frac{15}{28}\)

a)\(\frac{1}{2}:\frac{1}{5}+\frac{1}{3}:\frac{1}{5}+\frac{1}{6}:\frac{1}{5}\)

=\(\left(\frac{1}{2}+\frac{1}{3}+\frac{1}{6}\right):\frac{1}{5}\)

=\(1:\frac{1}{5}\)

=5

b)\(\frac{1515\text{×}161616}{151515\text{×}1616}\)

=1

\(A=\frac{3}{2}.\frac{4}{3}.\frac{5}{4}........\frac{2010}{2009}=\frac{3.4.5...2010}{2.3.4....2009}=\frac{2010}{2}=1005\)

\(B=\frac{1.2.3......99}{1.2.3.4.....100}=\frac{1}{100}\)