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Gợi ý: Sử dụng tính chất phân phối của phép nhân đối với phép cộng để nhóm thừa số chung ra ngoài.
a: \(=\dfrac{2\cdot136-28\cdot6+62\cdot3}{30}\cdot\dfrac{7}{8}=\dfrac{290}{30}\cdot\dfrac{7}{8}=\dfrac{29}{3}\cdot\dfrac{7}{8}=\dfrac{203}{24}\)
b: \(=\dfrac{3}{11}\cdot\dfrac{4}{11}+\dfrac{3}{13}\cdot\dfrac{4}{11}-\dfrac{1}{13}\)
\(=\dfrac{4}{11}\left(\dfrac{3}{11}+\dfrac{3}{13}\right)-\dfrac{1}{13}\)
\(=\dfrac{4}{11}\cdot\dfrac{72}{143}-\dfrac{1}{13}=\dfrac{167}{1573}\)
a) A = 3/7
b) B = 73/13
c) C = 37/7
d) D = 12
ba câu a) ,b) ,c) bn đổi ra hỗn số giúp mk nha
tick cho tớ nha
a) \(A=11\dfrac{3}{13}-\left(3\dfrac{4}{7}-6\dfrac{3}{13}\right)\)
\(=11\dfrac{3}{13}-3\dfrac{4}{7}-6\dfrac{3}{13}\)
\(=\left(11\dfrac{3}{13}-6\dfrac{3}{13}\right)-3\dfrac{4}{7}\)
\(=1\dfrac{3}{7}\)
b) \(B=\left(7\dfrac{4}{9}+3\dfrac{8}{13}\right)-5\dfrac{4}{9}\)
\(=7\dfrac{4}{9}+3\dfrac{8}{13}-5\dfrac{4}{9}\)
\(=\left(7\dfrac{4}{9}-5\dfrac{4}{9}\right)+3\dfrac{8}{13}\)
\(=2+3\dfrac{8}{13}\)
\(=5\dfrac{8}{13}\)
c) \(C=\dfrac{-2}{7}.\dfrac{5}{11}+\dfrac{-2}{7}.\dfrac{6}{11}+5\dfrac{4}{7}\)
\(=\dfrac{-2}{7}.\left(\dfrac{5}{11}+\dfrac{6}{11}\right)+5\dfrac{4}{7}\)
\(=\dfrac{-2}{7}+5\dfrac{4}{7}\)
\(=\dfrac{-5}{7}+\dfrac{12}{7}\)
\(=\dfrac{7}{7}=1\)
d) \(D=0,7.1\dfrac{3}{5}.30.0,375.\dfrac{4}{7}\)
\(=\dfrac{7}{10}.\dfrac{8}{5}.30.\dfrac{375}{1000}.\dfrac{4}{7}\)
\(=\dfrac{36}{5}\)
\(=7,2\)
a, \(4\dfrac{5}{37}\)-\(3\dfrac{4}{5}\)+ \(8\dfrac{15}{29}\)- \(3\dfrac{5}{37}\)+ \(6\dfrac{14}{29}\)
=(\(4\dfrac{5}{37}\)-\(3\dfrac{5}{37}\))+(\(8\dfrac{15}{29}\)+\(6\dfrac{14}{29}\))-\(3\dfrac{4}{5}\)
=(4-3)+(\(\dfrac{5}{37}\)-\(\dfrac{5}{37}\))+(8+6)+(\(\dfrac{15}{29}\)+\(\dfrac{14}{29}\))-3\(\dfrac{4}{5}\)
=1+ 15-\(3\dfrac{4}{5}\)=13-\(\dfrac{4}{5}\)=\(\dfrac{61}{5}\)
b, 60\(\dfrac{7}{13}\)+ 50\(\dfrac{8}{13}\)-11\(\dfrac{2}{13}\)
=(60+50-11)+(\(\dfrac{7}{13}\)+ \(\dfrac{8}{13}\)-\(\dfrac{2}{13}\))
=99+1=100
c, đáp án bằng \(\dfrac{-2}{3}\). bạn tự tính nha
A = \(\dfrac{1}{4}.\dfrac{7}{3}.12\)
= \(\dfrac{1.7.12}{4.3}\)
= \(7\)
@Nguyễn Thành Đăng
B = \(\dfrac{3}{8}.56.\dfrac{25}{7}.\left(-4\right)\)
= \(-\dfrac{3.56.25.4}{8.7}\)
= -3.100
= -300
@Nguyễn Thành Đăng
a: \(=\dfrac{4\cdot2+4\cdot9}{55}+\dfrac{5}{6}=\dfrac{4}{5}+\dfrac{5}{6}=\dfrac{49}{30}\)
b: \(=\dfrac{3}{2}\cdot\dfrac{3}{5}-\left(\dfrac{3}{7}+\dfrac{3}{20}\right)\cdot\dfrac{10}{3}\)
\(=\dfrac{9}{10}-\dfrac{81}{140}\cdot\dfrac{10}{3}\)
\(=\dfrac{9}{10}-\dfrac{27}{14}=\dfrac{-36}{35}\)
c: \(=15+\dfrac{3}{13}-3-\dfrac{4}{7}-8-\dfrac{3}{13}\)
\(=4-\dfrac{4}{7}=\dfrac{24}{7}\)
d: \(=\dfrac{-7}{9}\left(\dfrac{4}{11}+\dfrac{7}{11}\right)+5+\dfrac{7}{9}=5\)
\(B=\dfrac{10}{13}+\dfrac{3}{13}\cdot\dfrac{3}{11}+\dfrac{3}{13}\cdot\dfrac{8}{11}\)
\(B=\left(\dfrac{3}{13}+\dfrac{10}{13}\right)\cdot\left(\dfrac{3}{11}+\dfrac{8}{11}\right)\)
\(B=1\cdot1\)
\(B=1\)