Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
\(-\frac{12}{35}\div\frac{7}{11}-\frac{23}{35}\div\frac{7}{11}-\frac{5}{11}\)
\(=\left(-\frac{12}{35}-\frac{23}{35}\right)\div\frac{7}{11}-\frac{5}{11}\)
\(=-1\div\frac{7}{11}-\frac{5}{11}\)
\(=-\frac{11}{7}-\frac{5}{11}\)
\(=-\frac{156}{77}\)
c) 147x(14+7) và 14^3+7^3
147x(14+7)= 147x21=3087vaf 14^3 +7^3=2911+273=3184
suy ra 147x(14+7)>14^3+7^3
\(S=\frac{3}{1\cdot4}+\frac{3}{4\cdot7}+\frac{3}{7\cdot11}+\frac{3}{11\cdot14}+\frac{3}{14\cdot17}\)
\(S=\frac{4-1}{1\cdot4}+\frac{7-4}{4\cdot7}+\frac{11-7}{7\cdot11}+\frac{14-11}{11\cdot14}+\frac{17-14}{14\cdot17}\)
\(S=\frac{4}{1\cdot4}-\frac{1}{1\cdot4}+\frac{7}{7\cdot4}-\frac{4}{4\cdot7}+\frac{11}{7\cdot11}-\frac{7}{7\cdot11}+\frac{14}{11\cdot14}-\frac{11}{11\cdot14}+\frac{17}{14\cdot17}-\frac{14}{14\cdot17}\)
\(S=\frac{1}{1}-\frac{1}{4}+\frac{1}{4}-\frac{1}{7}+\frac{1}{7}-\frac{1}{11}+\frac{1}{11}-\frac{1}{14}+\frac{1}{14}-\frac{1}{17}\)
\(S=\frac{1}{1}-\frac{1}{17}=\frac{17}{17}-\frac{1}{17}=\frac{16}{17}\)
Bài làm
a) \(\frac{5}{7}.\frac{5}{11}+\frac{5}{7}.\frac{2}{11}-\frac{5}{7}.\frac{14}{11}\)
\(=\frac{5}{7}.\left(\frac{5}{11}+\frac{2}{11}-\frac{14}{11}\right)\)
\(=\frac{5}{7}.\left(-\frac{7}{11}\right)\)
\(=-\frac{5}{11}\)
b) \(M=3+\frac{1}{2}-2\frac{3}{3}+\frac{2}{3}-\frac{5}{6}\)
\(M=\frac{18}{6}+\frac{3}{6}-\frac{18}{6}+\frac{4}{6}-\frac{5}{6}\)
\(M=\left(\frac{18+3-18+4-5}{6}\right)\)
\(M=\frac{2}{6}\)
\(M=\frac{1}{3}\)
# Chúc bạn học tốt #
B=4*13/9*3-4/3*40/9
B=4/3*13/9-4/3*40/9
B=4/3*(13/9-40/9)
B=4/3*(-27)/9
B=4*(-3)/9
B=-4
A=6/7 + 1/7.(2/7+5/7)
A=6/7 + 1/7.7/7=6/7+1/7.1
A=6/7+1/7=7/7=1
1/3-(-2/7+1/3)
= 1/3 + 2/7 - 1/3
= (1/3 - 1/3) + 2/7
= 2/7