\(\frac{2}{9}\times\frac{5}{17}\:+\frac{7}{9}\:+\:\frac{2}{9}\times\frac{12}{17}\)
Mọi người giúp mình với nha, mình không có biết làm (╥﹏╥)
Tính theo cách lớp 6 :
\(\left(a\right)-\frac{3}{7}\div\frac{11}{5}+-\frac{3}{7}\div\frac{11}{6}+\frac{9}{7}\)
\(\left(b\right)\frac{4}{13}+-\frac{11}{5}+\frac{9}{13}+\frac{6}{5}-75\%\)
\(\left(c\right)-\frac{19}{17}\times\frac{4}{7}+\frac{19}{17}\times-\frac{3}{7}+1\frac{2}{17}\)
Làm được bao nhiêu hay bấy nhiêu ! Làm hết 3 tick, làm 2 câu 2 tick, 1 câu 1 tick. Sai ko tính
a) = -3/7 . 5/11 + -3/7 . 6/11 + 9/7
= -3/7. ( 5/11 + 6/11 ) + 9/7
= -3/7. 1 + 9/7
= -3/7 + 9/7
= 6/7
b) = 4/13 + 9/13 + -11/5 + 6/5 - 3/4
= 13/13 + -5/5 - 3/4
= 1 + (-1) - 3/4
= 0 - 3/4
= -3/4
c) = -19/17. 4/7 + 19/17. -3/7 + 19/17
= 19/17. -4/7 + 19/17. -3/7 + 19/17.1
= 19/17.( -4/7 + -3/7 + 19/17
= 19/17. -7/7 + 19/17
= 19/17. (-1) + 19/17
= -19/17 + 19/17
= 0
tk mk nha,thanks
\(\frac{-5}{7}.\frac{2}{11}+\frac{-5}{7}.\frac{9}{14}+\frac{12}{7}\)
\(\frac{12}{19}.\frac{7}{15}.\frac{-13}{17}.\frac{19}{12}\frac{17}{13}.\)
Giúp mình với ạ !!
b) \(\frac{12}{19}.\frac{7}{15}.\frac{-13}{17}.\frac{19}{12}.\frac{17}{13}=\frac{12}{19}.\frac{19}{12}.\frac{-13}{17}.\frac{17}{13}.\frac{7}{15}=1.\left(-1\right).\frac{7}{15}=\frac{-7}{15}\)
\(-\frac{5}{7}.\frac{2}{11}+-\frac{5}{7}.\frac{9}{14}+\frac{12}{7}=-\frac{5}{7}.\left(\frac{2}{11}+\frac{9}{14}\right)+\frac{12}{7}=-\frac{5}{7}.\frac{127}{154}+\frac{12}{7}=-\frac{635}{1078}+\frac{12}{7}=\frac{1213}{1078}\)
\(\frac{12}{19}.\frac{7}{15}.-\frac{13}{17}.\frac{19}{12}.\frac{17}{13}=\left(\frac{12}{19}.\frac{19}{12}\right).\left(-\frac{13}{17}.\frac{17}{13}\right).\frac{7}{15}=1.-1.\frac{7}{15}=-\frac{7}{15}\)
TÍNH BẰNG CÁCH THUẬN TIÊN NHẤT:
a,\(\frac{2001}{2002}\times\frac{5}{7}\times\frac{2002}{5}\times\frac{7}{2001}=\)
b,\(\frac{5}{7}\times\frac{7}{9}\times\frac{9}{11}\times\frac{11}{13}=\)
GIÚP MÌNH VỚI MÌNH ĐANG CẦN GẤP BẠN NÀO LÀM NHANH VÀ ĐÚNG MÌNH TICK CHO 5 LẦN ĐÚNG
\(a,\frac{2001}{2002}.\frac{5}{7}.\frac{2002}{5}.\frac{7}{2001}=\left(\frac{2001}{2002}.\frac{7}{2001}\right).\left(\frac{5}{7}.\frac{2002}{5}\right)\)
\(=\frac{7}{2002}.\frac{2002}{7}=1\)
\(b,\frac{5}{7}.\frac{7}{9}.\frac{9}{11}.\frac{11}{13}=\left(\frac{5}{7}.\frac{7}{9}\right).\left(\frac{9}{11}.\frac{11}{13}\right)=\frac{5}{9}.\frac{9}{13}\)
\(=\frac{5}{13}\)
xin lỗi mình k nhầm
Mai mình k trả lại
Tìm x biết:
a)\(\frac{3}{5}\times x-\frac{1}{5}=\frac{4}{5}\)
b)\(\frac{4}{7}+\frac{5}{7}\div x=1\)
c)\(\frac{-12}{7}\times\left(\frac{3}{4}-x\right)\times\frac{1}{4}=-1\)
d)\(x\div\frac{17}{8}=\frac{-2}{5}\times\frac{-9}{17}+3\)
a) \(\frac{3}{5}.x-\frac{1}{5}=\frac{4}{5}\)
\(\Leftrightarrow\frac{3}{5}.x=\frac{4}{5}+\frac{1}{5}\)
\(\Leftrightarrow\frac{3}{5}.x=1\)
\(\Leftrightarrow x=1:\frac{3}{5}\)
\(\Leftrightarrow x=\frac{5}{3}\)
Vậy : \(x=\frac{5}{3}\)
b) \(\frac{4}{7}+\frac{5}{7}:x=1\)
\(\Leftrightarrow\frac{5}{7}:x=1-\frac{4}{7}\)
\(\Leftrightarrow\frac{5}{7}:x=\frac{3}{7}\)
\(\Leftrightarrow x=\frac{5}{7}:\frac{3}{7}\)
\(\Leftrightarrow x=\frac{5}{3}\)
Vậy : \(x=\frac{5}{3}\)
c) \(-\frac{12}{7}.\left(\frac{3}{4}-x\right).\frac{1}{4}=-1\)
\(\Leftrightarrow\frac{-12.1}{7.4}.\left(\frac{3}{4}-x\right)=-1\)
\(\Leftrightarrow-\frac{3}{7}.\left(\frac{3}{4}-x\right)=-1\)
\(\Leftrightarrow\frac{3}{4}-x=-1:\left(-\frac{3}{7}\right)\)
\(\Leftrightarrow\frac{3}{4}-x=\frac{7}{3}\)
\(\Leftrightarrow x=\frac{3}{4}-\frac{7}{3}=-\frac{19}{12}\)
Vậy : \(x=-\frac{19}{12}\)
d) \(x:\frac{17}{8}=-\frac{2}{5}.-\frac{9}{17}+3\)
\(\Leftrightarrow x:\frac{17}{8}=\frac{273}{85}\)
\(\Leftrightarrow x=\frac{273}{85}.\frac{17}{8}\)
\(\Leftrightarrow x=\frac{273}{40}\)
Vậy : \(x=\frac{273}{40}\)
\(\)
Giup mình làm đề này nha, mình hậu tạ mọi người rất nhiều!
Tính nhanh: \(A=\frac{50-\frac{4}{13}+\frac{2}{15}-\frac{2}{17}}{100-\frac{8}{13}+\frac{4}{15}-\frac{4}{17}}\)
\(B=\frac{1}{19}+\frac{9}{19.29}+\frac{9}{29.39}+.......+\frac{9}{1999.2009}\)
\(A=\frac{50-\frac{4}{13}+\frac{2}{15}-\frac{2}{17}}{100-\frac{8}{13}+\frac{4}{15}-\frac{4}{17}}\)
\(=\frac{50-\frac{4}{13}+\frac{2}{15}-\frac{2}{17}}{2\left(50-\frac{4}{13}+\frac{2}{15}-\frac{2}{17}\right)}\)
\(=\frac{1}{2}\)
\(B=\frac{1}{19}+\frac{9}{19.29}+\frac{9}{29.39}+......+\frac{9}{1999.2009}\)
\(=\frac{1}{19}+\frac{9}{10}\left(\frac{1}{19}-\frac{1}{29}+\frac{1}{19}-\frac{1}{39}+....+\frac{1}{1999}-\frac{1}{2009}\right)\)
\(=\frac{1}{19}+\frac{9}{10}\left(\frac{1}{19}-\frac{1}{2009}\right)\)
\(=\frac{1}{19}+\frac{9}{10}\cdot\frac{1990}{38171}\)
\(=\frac{200}{2009}\)
cái này......hình như ở trên học 24 mà
NĐT_2004_asd nằm mơ đi con nhé nếu giải mày đc 20 điểm hả
\(\frac{3}{2}-\frac{5}{6}+\frac{7}{12}-\frac{9}{20}+\frac{11}{30}-\frac{13}{42}+\frac{15}{56}-\frac{17}{72}\)
GIÚP MÌNH VỚI
\(\frac{3}{2}-\frac{5}{6}+\frac{7}{12}-\frac{9}{20}+\frac{11}{30}-\frac{13}{42}+\frac{15}{56}-\frac{17}{72}\)
\(=\frac{3}{1.2}-\frac{5}{2.3}+\frac{7}{3.4}-\frac{9}{4.5}+\frac{11}{5.6}-\frac{13}{6.7}+\frac{15}{7.8}-\frac{17}{8.9}\)
\(=\left(1+\frac{1}{2}\right)-\left(\frac{1}{2}+\frac{1}{3}\right)+\left(\frac{1}{3}+\frac{1}{4}\right)-\left(\frac{1}{4}+\frac{1}{5}\right)+\left(\frac{1}{5}+\frac{1}{6}\right)-\left(\frac{1}{6}+\frac{1}{7}\right)\)
\(+\left(\frac{1}{7}+\frac{1}{8}\right)-\left(\frac{1}{8}+\frac{1}{9}\right)\)
\(=1+\frac{1}{2}-\frac{1}{2}-\frac{1}{3}+\frac{1}{3}+\frac{1}{4}-\frac{1}{4}-\frac{1}{5}+\frac{1}{5}+\frac{1}{6}-\frac{1}{6}-\frac{1}{7}+\frac{1}{7}+\frac{1}{8}-\frac{1}{8}-\frac{1}{9}\)
\(=1-\frac{1}{9}=\frac{8}{9}\)
a) \(\frac{4}{15}\times\frac{7}{9}+\frac{4}{15}\times\frac{2}{9}\)
b)\(\frac{13}{19}\times\frac{23}{11}-\frac{13}{19}\times\frac{8}{11}-\frac{13}{19}\times\frac{4}{11}\)
Giúp mình với nhé!
\(a.\) \(\frac{4}{15}.\frac{7}{9}+\frac{4}{15}.\frac{2}{9}\)
\(=\frac{4}{15}\left(\frac{7}{9}+\frac{2}{9}\right)\)
\(=\frac{4}{15}.\frac{9}{9}\)
\(=\frac{4}{15}.1\)
\(=\frac{4}{15}\)
\(b.\) \(\frac{13}{19}.\frac{23}{11}-\frac{13}{19}.\frac{8}{11}-\frac{13}{19}.\frac{4}{11}\)
\(=\frac{13}{19}\left(\frac{23}{11}-\frac{8}{11}-\frac{4}{11}\right)\)
\(=\frac{13}{19}.\frac{11}{11}\)
\(=\frac{13}{19}.1\)
\(=\frac{13}{19}\)
a)4/15 x(7/9+2/9)=4/15x1=4/15
b)13/19x(23/11-8/11-4/11)13/19x1=13/19
A) \(\frac{4}{15}x\frac{7}{9}+\frac{4}{15}x\frac{2}{9}\)
\(=\frac{28}{135}+\frac{8}{135}\)
\(=\frac{36}{135}=\frac{4}{15}\)
B) \(\frac{13}{19}x\frac{23}{11}-\frac{13}{19}x\frac{8}{11}-\frac{13}{19}x\frac{4}{11}\)
\(=\frac{299}{209}-\frac{104}{209}-\frac{52}{209}\)
\(=\frac{143}{209}\)
B=\(1\frac{6}{41}\times\left(\frac{12+\frac{12}{19}-\frac{12}{37}-\frac{12}{53}}{3+\frac{1}{3}-\frac{3}{37}-\frac{3}{53}}\div\frac{4+\frac{4}{17}+\frac{4}{19}+\frac{4}{2006}}{5+\frac{5}{17}+\frac{5}{19}+\frac{5}{2006}}\right)\times\frac{124242423}{237373735}\)
GIÚP MÌNH VỚI ! ^_^
Giúp tôi bài này với ai giải hết được cho đúng luôn:) \(7-\frac{12}{13};7\frac{2}{5}-3\frac{2}{9};4\frac{2}{5}-2\frac{6}{7};17\frac{2}{31}-\left(\frac{15}{17}+6\frac{2}{31}\right)\).Nhớ làm rõ ra nhé nếu không sẽ không được tính