Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
a)\(\frac{2}{3}+\frac{3}{4}+\frac{5}{6}\)
\(=\frac{8+9+10}{12}\)
\(=\frac{27}{12}=\frac{9}{4}\)
b)\(\frac{15}{8}-\frac{7}{12}+\frac{5}{6}\)
\(=\frac{45-14+20}{24}\)
\(=\frac{51}{24}=\frac{17}{8}\)
2)
a)\(\frac{2}{5}+\frac{7}{13}+\frac{3}{5}+\frac{1}{7}\)
\(=\frac{2}{5}+\frac{3}{5}+\frac{7}{13}+\frac{1}{7}\)
\(=1+\frac{7}{13}+\frac{1}{7}\)
\(=\frac{20}{13}+\frac{1}{7}\)
\(=\frac{153}{91}\)
Tí tớ trả lời tiếp
A = -10/3 + 19/6.7/5 - 19/3.1/10 + 19/10.4/3
A = 1/30.(-10.10 + 19.7 - 19.1 + 19.4)
A = 1/30.(-100 + 19.11 - 19)
A = 1/30.(-100 + 19.10)
A = 1/30.(-100 + 190)
A = 1/30.90
A = 3
a ) \(\frac{7}{19}.\frac{8}{11}+\frac{3}{11}.\frac{7}{19}+\frac{-12}{19}\)
\(=\frac{7}{19}.\left(\frac{8}{11}+\frac{3}{11}\right)+\frac{-12}{19}\)
\(=\frac{7}{19}.\frac{11}{11}+\frac{-12}{19}\)
\(=\frac{7}{19}.1+\frac{-12}{19}\)
\(=\frac{7}{19}+\frac{-12}{19}\)
\(=\frac{7+\left(-12\right)}{19}\)
\(=-\frac{5}{19}\)
b ) \(\frac{-7}{25}.\frac{39}{-14}.\frac{50}{78}=\frac{-7.39.50}{25.-14.78}=\frac{-1.1.2}{1.-2.2}=\frac{-2}{-4}=\frac{1}{2}\)
c ) \(\left(\frac{3}{8}+\frac{-3}{4}+\frac{7}{12}\right):\frac{5}{6}+\frac{1}{2}\)
\(=\frac{5}{24}:\frac{5}{6}+\frac{1}{2}\)
\(=\frac{5}{24}.\frac{6}{5}+\frac{1}{2}\)
\(=\frac{1}{4}+\frac{1}{2}\)
\(=\frac{3}{4}\)
a)\(\frac{7}{19}.\frac{8}{11}+\frac{3}{11}.\frac{7}{19}+\frac{-12}{19}=\frac{7}{19}.\frac{8}{11}+\frac{3}{11}.\frac{7}{19}+\frac{7}{19}.\frac{-12}{7}=\frac{7}{19}.\left(\frac{8}{11}+\frac{3}{11}+-\frac{12}{7}\right)=\frac{7}{19}.\left(\frac{-5}{7}\right)=-\frac{5}{19}\)
b)\(\frac{-7}{25}.\frac{39}{-14}.\frac{50}{78}=\frac{\left(-7\right).39.50}{25.\left(-14\right).78}=\frac{\left(-7\right).3.13.2.5.5}{5.5.\left(-7\right).2.2.13.3}=\frac{1}{2}\)
c)\(\left(\frac{3}{8}+\frac{-3}{4}+\frac{7}{12}\right):\frac{5}{6}+\frac{1}{2}=\frac{5}{24}:\frac{5}{6}+\frac{1}{2}=\frac{2}{7}+\frac{1}{2}=\frac{11}{14}\)
\(a.\frac{108}{119}.\frac{107}{211}+\frac{108}{119}.\frac{104}{211}=\frac{108}{119}.\left(\frac{107}{211}+\frac{104}{211}\right)=\frac{108}{119}.1=108\)
Muốn cho số có hai chữ số giống nhau và chia hết cho 2 thì số đó phải là một trong các số 22, 44, 66, 88. Bây giờ ta tìm trong những số này số mà chia cho 5 thì dư 3.
Đó là số 88.
Xem thêm tại: http://loigiaihay.com/bai-99-trang-39-sgk-toan-6-tap-1-c41a3896.html#ixzz4xczZ4dOb
e) \(E=0,7.2\frac{2}{3}.20.0,375.\frac{5}{28}\)
\(=\left(0,7.20\right)\left(2\frac{2}{3}.0,375\right)\frac{5}{28}\)
\(=14.1.\frac{5}{28}\)
\(=14.\frac{5}{28}\)
\(=\frac{5}{2}\)
f) \(F=\left(9,75.21\frac{3}{7}+\frac{39}{4}.18\frac{4}{7}\right)\frac{15}{78}\)
\(=\left(\frac{39}{4}.21\frac{3}{7}+\frac{39}{4}.18\frac{4}{7}\right)\frac{15}{78}\)
\(=\frac{39}{4}\left(21\frac{3}{7}+18\frac{4}{7}\right)\frac{15}{78}\)
\(=\frac{39}{4}.40.\frac{15}{78}\)
\(=390.\frac{15}{78}\)
\(=78\)
Chúc bạn học tốt môn Toán!!!
Mình ko ghi đề đâu
\(A=49\frac{8}{23}-5\frac{7}{32}-14\frac{8}{23}=\left(49\frac{8}{23}-14\frac{8}{23}\right)-5\frac{7}{32}=35-5\frac{7}{32}=29\frac{25}{32}\)
\(B=71\frac{38}{45}-43\frac{8}{45}+1\frac{17}{57}=\left(71\frac{38}{45}-43\frac{8}{45}\right)+1\frac{17}{57}=28\frac{2}{3}+1\frac{17}{57}=29\frac{55}{57}\)
\(C=-\frac{3}{7}.\left(\frac{5}{9}+\frac{4}{9}\right)+2\frac{3}{7}=-\frac{3}{7}.1+2\frac{3}{7}=-\frac{3}{7}+2\frac{3}{7}=2\)
a) \(\left(4\frac{2}{3}-2\frac{2}{5}+7\frac{7}{13}\right)-\left(3\frac{5}{23}-6\frac{6}{13}\right)\)
= \(4\frac{2}{3}-2\frac{2}{5}+7\frac{7}{13}-3\frac{5}{23}+6\frac{6}{13}\)
= \(\left(4\frac{2}{3}-2\frac{2}{5}\right)+\left(7\frac{7}{13}+6\frac{6}{13}\right)-3\frac{5}{23}\)
= \(2\frac{4}{15}+14-3\frac{5}{23}\)
= \(16\frac{4}{15}-3\frac{5}{23}\)
= \(13\frac{17}{345}\)
XIN LỖI NHA, MÌNH KO LÀM ĐƯỢC XONG CÂU b) , MONG BẠN THÔNG CẢM CHO MÌNH, KHI NÀO MÌNH NGHĨ RA CÂU b) MÌNH SẼ TRẢ LỜI
\(\frac{-3}{5}.\left(\frac{5}{7}+\frac{3}{7}+\frac{6}{7}\right)\)
=\(\frac{-3}{5}.\)\(\frac{14}{7}\)
=\(-\frac{3}{5}.2\)
=-6/5