B=522+313−12413−211+32
Đặt \(S=\frac{5}{22}+\frac{3}{13}-\frac{1}{2}\)
=> S= \(\frac{-6}{143}\)
Đặt \(H=\frac{4}{13}-\frac{2}{11}+\frac{3}{2}\)
=> H = \(\frac{465}{286}\)
Khi đó B = \(\frac{\frac{-6}{143}}{\frac{465}{286}}\)=\(\frac{-4}{155}\)
Tính bằng cách hợp lí :
a , \(4\frac{3}{4}+\left(-0,37\right)+\frac{1}{8}+\left(-1,28\right)+\left(-2,5\right)+3\frac{1}{2}\)
b ,\(\frac{3}{5.7}+\frac{3}{7.9}+...+\frac{3}{59\cdot61}\)
c,\(\frac{\frac{5}{22}+\frac{3}{13}-\frac{1}{2}}{\frac{4}{13}-\frac{2}{11}+\frac{3}{2}}\)
Tính nhanh:
a)\(\frac{24\cdot47-23}{24+47-23}\cdot\frac{3+\frac{3}{7}-\frac{3}{11}+\frac{3}{1001}-\frac{3}{13}}{\frac{9}{1001}-\frac{9}{13}+\frac{9}{7}-\frac{9}{11}+9}\)
b)\(\frac{1+2+2^2+...+2^{2012}}{2^{2014}-2}\)
điền số thích hợp vào chỗ trống:
a, \(\frac{-11}{13}
\(M=\frac{3}{2}-\frac{5}{6}+\frac{7}{12}-\frac{9}{20}+\frac{11}{30}-\frac{13}{42}+\frac{15}{56}-\frac{17}{72}\)
Tính nhanh tổng sau:
\(M=\frac{3}{2}-\frac{5}{6}+\frac{7}{12}-\frac{9}{20}+\frac{11}{30}-\frac{13}{42}+\frac{15}{56}-\frac{17}{72}\)
\(P=\frac{\frac{2}{3}-\frac{1}{4}+\frac{5}{11}}{\frac{5}{12}+1-\frac{7}{11}}\)
Tính B=$\frac{1}{3} \frac{1}{6}\left(1 2\right) \frac{1}{9}\left(1 2 3\right) ... \frac{1}{6045}\left(1 2 3 ... 2015\right)$13 16 (1 2) 19 (1 2 3) ... 16045 (1 2 3 ... 2015)
\(\frac{\frac{2}{3}-\frac{1}{4}+\frac{5}{11}}{\frac{5}{12}+1-\frac{7}{11}}\)
Tính nhanh\(\frac{\left(27\frac{5}{19}-26\frac{4}{13}\right).\left(\frac{3}{4}+\frac{19}{59}-\frac{3}{118}\right)}{\left(\frac{3}{4}+x\right)\frac{27}{33}}\) =1. Tìm x