quy đồng mẫu số các phân số
a) \(\frac{5}{2^2.3},\frac{7}{2^3.11}\) b) \(\frac{3}{-20},\frac{-11}{-30},\frac{7}{15}\)
c) \(\frac{-6}{-35},\frac{27}{-180},\frac{-3}{-28}\) d) \(\frac{-5}{5},\frac{8}{7}\)
e) \(3,\frac{-3}{5},\frac{-5}{6}\) f) \(\frac{-9}{7},\frac{-19}{15},-1\)
\(M=\frac{3}{2}-\frac{5}{6}+\frac{7}{12}-\frac{9}{20}+\frac{11}{30}-\frac{13}{42}+\frac{15}{56}-\frac{17}{72}\)
Tính nhanh tổng sau:
\(M=\frac{3}{2}-\frac{5}{6}+\frac{7}{12}-\frac{9}{20}+\frac{11}{30}-\frac{13}{42}+\frac{15}{56}-\frac{17}{72}\)
Tìm các dãy tỉ số bằng nhau:
a) \(\frac{x}{4}=\frac{y}{3}=\frac{3}{9}\)và x-3y+4z=62
b) \(\frac{x}{y}=\frac{7}{20};\frac{y}{z}=\frac{5}{8}\)và 2x+5y-2z=100
c) \(\frac{x}{y}=\frac{9}{7};\frac{y}{z}=\frac{7}{3}\)và x-y+z=(-15)
d) \(\frac{6}{11}x=\frac{9}{2}y=\frac{18}{5}z\) và -x+y+z=(-120)
\(B=\frac{4+\frac{4}{5}+\frac{4}{155}-\frac{4}{1555}+\frac{4}{235}}{8+\frac{8}{5}+\frac{16}{310}+\frac{8}{235}-\frac{8}{1555}}.\frac{1+\frac{1}{2}+\frac{1}{3}+\frac{1}{4}}{4+\frac{3}{2}+\frac{3}{4}}\)
\(B=\frac{1}{2}\)+\(\frac{-1}{5}\)+\(\frac{-5}{7}\)+\(\frac{1}{6}\)+\(\frac{-3}{35}\)+\(\frac{1}{3}\)+\(\frac{1}{41}\)
E=40+\(\frac{3}{8^{ }}\)+\(\frac{7}{8^2}\)+\(\frac{5}{8^3}\)+\(\frac{32}{8^5}\)
F=\(\frac{147}{7^3}\)+4+\(\frac{35}{7^7}\)+\(\frac{4}{7^2}\)+\(\frac{27}{7^5}\)+\(\frac{-9}{7}\)
đây là toán lớp 6 lên các bạn đừng thắc mắc
CMR;\(\frac{3}{4}+\frac{8}{9}+\frac{15}{16}+.....+\frac{2499}{2500}>48\)
\(P=\frac{\frac{2}{3}-\frac{1}{4}+\frac{5}{11}}{\frac{5}{12}+1-\frac{7}{11}}\)