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\(-23.63+23.21-58.23\)
\(=-23.\left(63+21-58\right)\)
\(=-23.26\)
\(=-598\)
k mik nha
\(\dfrac{1}{4}-\dfrac{1}{3}+\dfrac{5}{12}\\ =\dfrac{3}{12}-\dfrac{4}{12}+\dfrac{5}{12}\\ =\dfrac{3-4+5}{12}\\ =\dfrac{4}{12}\\ =\dfrac{1}{3}\)
\(\left(1-\frac{1}{3}\right).\left(1-\frac{1}{6}\right).\left(1-\frac{1}{10}\right)...\left(1-\frac{1}{190}\right)\)
\(=\frac{2}{3}.\frac{5}{6}.\frac{9}{10}...\frac{189}{190}\)
\(=\frac{4}{6}.\frac{10}{12}.\frac{18}{20}...\frac{378}{380}\)
\(=\frac{1.4}{2.3}.\frac{2.5}{3.4}.\frac{3.6}{4.5}...\frac{18.21}{19.20}\)
\(=\frac{1.2.3...18}{2.3.4...19}.\frac{4.5.6...21}{3.4.5...20}\)
\(=\frac{1}{19}.\frac{21}{3}\)
\(=\frac{1}{19}.7=\frac{7}{19}\)
\(\left(1-\frac{1}{3}\right).\left(1-\frac{1}{6}\right).\left(1-\frac{1}{10}\right)...\left(1-\frac{1}{190}\right)\)
\(=\frac{2}{3}.\frac{5}{6}.\frac{9}{10}....\frac{189}{190}\)
\(=\frac{4}{6}.\frac{10}{12}.\frac{18}{20}....\frac{378}{380}\)
\(=\frac{1.4}{2.3}.\frac{2.5}{3.4}.\frac{3.6}{4.5}....\frac{18.21}{19.20}\)
\(=\frac{1.2.3....18}{2.3.4....19}.\frac{4.5.6...21}{3.4.5....20}\)
\(=\frac{1}{19}.\frac{21}{3}\)
\(=\frac{1}{19}.7=\frac{7}{19}\)
Ủng hộ mk nha !!! ^_^
30-[50-(9-4)2]+20150
=30-[50-52]+20150
=30-[50-25]+20150
=30-25+20150
=30-25+1
=5+1
=6
A = - [-806 - (-791) + 2012] - (806 - 1791)
A = 806 - 791 + 2012 - 806 + 1791
A = (806 - 806) + (1791 - 791)
A = 1000
B = 9 - (119).34 + 119.(-77) - (-119).11
B = 9 - 119(34 + 77 - 11)
B = 9 - 119.100
B = 9 - 11900
B = - 11891