\(=\dfrac{1}{5}+\dfrac{14}{25}=\dfrac{5}{25}+\dfrac{14}{25}=\dfrac{19}{25}\)
\(\dfrac{9}{45}+\dfrac{14}{25}=\dfrac{1}{5}+\dfrac{14}{25}=\dfrac{5+14}{25}=\dfrac{19}{25}\)
\(=\dfrac{1}{5}+\dfrac{14}{25}=\dfrac{5}{25}+\dfrac{14}{25}=\dfrac{19}{25}\)
\(\dfrac{9}{45}+\dfrac{14}{25}=\dfrac{1}{5}+\dfrac{14}{25}=\dfrac{5+14}{25}=\dfrac{19}{25}\)
Bài 2: Tính nhanh:
a) \(\dfrac{3}{4}\cdot\dfrac{8}{9}\cdot\dfrac{15}{16}\cdot\dfrac{24}{25}\cdot.....\cdot\dfrac{120}{121}\cdot\dfrac{143}{144}\)
b)\(\dfrac{5}{9}\cdot\dfrac{21}{25}\cdot\dfrac{45}{49}\cdot\dfrac{77}{81}\cdot.....\dfrac{357}{361}\cdot\dfrac{437}{441}\)
ai làm đúng mk dùng 3nick mk tick cho :))))
Bài 5: ( Đề 1) Viết các PS sau thành PS thập phân
a) \(\dfrac{3}{25}\) =.............................. b) \(\dfrac{7}{8}\) =................................
c) \(\dfrac{9}{45}\) =..............................
Tính NHANH
\(\dfrac{5}{14}\) + \(\dfrac{7}{13}\) + \(\dfrac{26}{25}\)
\(\dfrac{5}{14}\) x \(\dfrac{7}{13}\) x \(\dfrac{26}{25}\)
\(B=\dfrac{5}{2x3}-\dfrac{8}{3x5}+\dfrac{11}{5x6}-\dfrac{14}{6x8}+\dfrac{18}{8x10}-\dfrac{22}{10x12}+\dfrac{25}{12x13}\)
giúp iem vs ạ :>
a)\(\dfrac{7}{8}\)x\(\dfrac{3}{13}\)+\(\dfrac{4}{9}\)x\(\dfrac{4}{13}\)
b)\(\dfrac{6}{5}\)+\(\dfrac{7}{3}\)+\(\dfrac{8}{9}\)
c)23: \(\dfrac{5}{14}\)+\(\dfrac{6}{7}\)+\(\dfrac{4}{9}\)
d)\(4\dfrac{1}{4}\)+\(7\dfrac{3}{7}\)-\(2\dfrac{4}{17}\)
e)8-(9\(\dfrac{2}{11}\)+\(\dfrac{8}{33}\))
VÒNG 2
Bài 1: Mèo con nhanh nhẹn
| \(\dfrac{1}{2}\) + \(\dfrac{1}{12}\) | 2 + \(\dfrac{1}{6}\) | \(\dfrac{1}{20}\) | 1 - \(\dfrac{1}{9}\) | |
| \(\dfrac{1}{15}\) + \(\dfrac{2}{15}\) | \(\dfrac{1}{2}\) + \(\dfrac{2}{3}\) | \(\dfrac{7}{12}\) | \(\dfrac{4}{12}\) | |
| \(\dfrac{9}{14}\)+ \(\dfrac{1}{14}\) | 1 + \(\dfrac{1}{6}\) | \(\dfrac{1}{4}\) - \(\dfrac{1}{5}\) | \(\dfrac{1}{3}\) - \(\dfrac{2}{9}\) | |
| \(\dfrac{3}{2}\) + \(\dfrac{2}{3}\) | \(\dfrac{1}{5}\) | 1 - \(\dfrac{8}{9}\) | ||
| \(\dfrac{5}{7}\) | 1 - \(\dfrac{2}{3}\) | \(\dfrac{1}{3}\) + \(\dfrac{5}{9}\) |
9 - 3 x ( X - 9 ) = 6
4 + 6 x ( X + 1 ) 70
\(\dfrac{X}{13}+\dfrac{15}{26}=\dfrac{46}{52}\)
\(\dfrac{11}{14}-\dfrac{3}{X}=\dfrac{5}{14}\)
5 x ( 3 + 7 x X ) = 40
X x 6 + 12 : 3 = 120
X x 3,7 + X x 6,3 = 120
( 15 x 24 - X ) : 0,25 = 100 : \(\dfrac{1}{4}\)
71 + 65 x 4 = \(\dfrac{X+140}{X}\)+ 260
( X +1 ) + ( X + 4 ) + ( x + 7 ) + ...... + (X + 28 ) = 155
đây là bài tìm X
Tính thuận tiện :
M = 3 + \(\dfrac{4}{9}\) x \(\dfrac{7}{25}\) x \(\dfrac{27}{12}\) x \(3\dfrac{4}{7}\) - \(\dfrac{7}{25}\)
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