Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
= mười ko ha ngoc chi
mình trả lời mấy lần nhưng toàn hiên ra = 1 thôi à
Bài 1: Tính
a, 1/2 x 2/3 x 3/4 = 1/4
b, 7/8 x 8/9 x 9/10 = 7/10
c, 5/14 x 7/15 x 28/7 = 2/3
d, 2 x 1/2 x 3 x 1/3 x 4 x 1/4 x 5 x 1/5 = 1
Bài 2: Tính
a, 7/20 - ( 5/8 - 3/5 ) = 7/20 - 1/40 = 14/40 - 1/40 = 13/40
b, 5/6 + ( 5/9 - 1/4 ) = 5/6 + 11/36 = 30/36 + 11/36 = 41/36
c, 9/10 - ( 2/5 + 3/10 ) + 7/20 = 9/10 - 7/10 + 7/20 = 2/10 + 7/20 = 4/20 + 7/20 = 11/20.
Bài 3: Tìm x:
a, 1/2 + x = 5/6
x = 5/6 - 1/2
x = 1/3
b, 5/6 - x = 1/3
x = 5/6 - 1/3
x = 1/2
c, x - 1/mấy vậy bạn
d, 1/3 x x = 1/6
x = 1/6 : 1/3
x = 1/2
25 + 25 + 25 + 25 + 25 + 25 +25 + 25=25x8=200
45 + 45 + 45 + 45 + 15 + 15 + 15 + 15=(45x4)+(15x4)=180+60=240
a) \(\dfrac{2}{9}+\dfrac{5}{9}=\dfrac{7}{9};\dfrac{5}{9}+\dfrac{2}{9}=\dfrac{7}{9}\)
Vậy: \(\dfrac{2}{9}+\dfrac{5}{9}=\dfrac{5}{9}+\dfrac{2}{9}\)
b) \(\dfrac{3}{25}+\dfrac{4}{25}+\dfrac{7}{25}=\dfrac{14}{25};\dfrac{3}{25}+\dfrac{7}{25}+\dfrac{4}{25}=\dfrac{14}{25}\)
Vậy: \(\dfrac{3}{25}+\dfrac{4}{25}+\dfrac{7}{25}=\dfrac{3}{25}+\dfrac{7}{25}+\dfrac{4}{25}\)
\(\dfrac{8}{9}-\dfrac{5}{9}=\dfrac{3}{9}=\dfrac{1}{3}\)
\(\dfrac{18}{25}-\dfrac{13}{25}=\dfrac{5}{25}=\dfrac{1}{5}\)
\(\dfrac{7}{5}-\dfrac{4}{5}=\dfrac{3}{5}\)
\(\dfrac{36}{41}-\dfrac{37}{41}=-\dfrac{1}{41}\)
\(\dfrac{8}{9}-\dfrac{5}{9}=\dfrac{8-5}{9}=\dfrac{3}{9}=\dfrac{1}{3}\)
\(\dfrac{18}{25}-\dfrac{13}{25}=\dfrac{18-13}{25}=\dfrac{5}{25}=\dfrac{1}{5}\)
\(\dfrac{7}{5}-\dfrac{4}{5}=\dfrac{7-4}{5}=\dfrac{3}{5}\)
\(\dfrac{36}{41}-\dfrac{37}{41}=\dfrac{36-37}{41}\) (câu này hình như lỗi đề em nhé, vì lớp 4 chưa học số âm)
a) \(\dfrac{7}{9}\times\dfrac{13}{25}\times\dfrac{9}{7}=\left(\dfrac{7}{9}\times\dfrac{9}{7}\right)\times\dfrac{13}{25}=1\times\dfrac{13}{25}=\dfrac{13}{25}\)
b) \(\dfrac{5}{9}\times\dfrac{21}{25}+\dfrac{21}{25}\times\dfrac{4}{9}\)
\(=\dfrac{21}{25}\times\left(\dfrac{5}{9}+\dfrac{4}{9}\right)\)
\(=\dfrac{21}{25}\times1=\dfrac{21}{25}\)
c) \(\dfrac{19}{5}\times\dfrac{11}{16}-\dfrac{9}{5}\times\dfrac{11}{16}\)
\(=\dfrac{11}{16}\times\left(\dfrac{19}{5}-\dfrac{9}{5}\right)\)
\(=\dfrac{11}{16}\times2=\dfrac{22}{16}=\dfrac{11}{8}\)
\(\frac{5}{14}\)x \(\frac{7}{13}\) x \(\frac{26}{25}\) = \(\frac{91}{455}\)