\(\frac{15}{37}\)x{\(\frac{38}{41}\)_\(\frac{74}{45}\)} _ \(\frac{38}{41}\)x { \(\frac{15}{37}\)+ \(\frac{82}{76}\)}
tính bằng cách thuận tiện nhất
\(\frac{15}{37}.\left\{\frac{38}{41}-\frac{74}{45}\right\}-\frac{38}{41}\left\{\frac{15}{37}+\frac{82}{76}\right\}\)
Mọi người giúp mk nha,thanks
15/37x(38/41-74/45)-38/41x(15/37+82/76)
\(=\dfrac{15}{37}\cdot\dfrac{38}{41}-\dfrac{15}{37}\cdot\dfrac{74}{45}-\dfrac{38}{41}\cdot\dfrac{15}{37}-\dfrac{38}{41}\cdot\dfrac{82}{76}\)
\(=\dfrac{-1}{3}\cdot2-\dfrac{1}{2}\cdot2=-\dfrac{2}{3}-1=-\dfrac{5}{3}\)
Tính nhanh
a)47/53x(17/3-53/47)+17/3x(6/17-47/53)
b)15/37x(38/41-75/45)-38/41x(15/37-82/76)
c)-41/32x(15/8-16/41)+15/8x(41/32-8/3)
BT2: Tính nhanh:
1) \(\dfrac{15}{37}\left(\dfrac{38}{41}-\dfrac{74}{45}\right)-\dfrac{38}{41}\left(\dfrac{15}{37}+\dfrac{82}{76}\right)\)
2)\(\dfrac{47}{53}\left(\dfrac{17}{3}-\dfrac{53}{47}\right)+\dfrac{17}{3}\left(\dfrac{6}{17}-\dfrac{47}{53}\right)\)
1: \(=\dfrac{15}{37}\cdot\dfrac{38}{41}-\dfrac{15}{37}\cdot\dfrac{74}{45}-\dfrac{38}{41}\cdot\dfrac{15}{37}-\dfrac{38}{41}\cdot\dfrac{82}{76}\)
\(=\dfrac{-2}{3}-1=-\dfrac{5}{3}\)
2: \(=\dfrac{47}{53}\cdot\dfrac{17}{3}-\dfrac{47}{53}\cdot\dfrac{53}{47}+\dfrac{17}{3}\cdot\dfrac{6}{17}-\dfrac{17}{3}\cdot\dfrac{47}{53}\)
\(=-1+2=1\)
tính bằng cách thuận tiện :
a)\(\frac{37}{25}:\frac{5}{4}:\frac{74}{25}\)
\(\frac{6}{11}:\frac{4}{3}:\frac{5}{11}:\frac{4}{3}\)
a: \(=\dfrac{37}{25}\cdot\dfrac{25}{74}\cdot\dfrac{4}{5}=\dfrac{1}{2}\cdot\dfrac{4}{5}=\dfrac{2}{5}\)
b: \(=\dfrac{6}{11}\cdot\dfrac{11}{5}:\dfrac{16}{9}=\dfrac{6}{5}\cdot\dfrac{9}{16}=\dfrac{54}{80}=\dfrac{27}{40}\)
Tính bằng cách thuận tiện nhất :
a) 384 : 25 : 4
b)\(\frac{37}{25}:\frac{5}{4}:\frac{74}{25}\)
c)380 : (38x2)
d)\(\frac{6}{11}:\frac{4}{3}:\frac{5}{11}:\frac{4}{3}\)
a)=384:(25*4)=384:100=3,84.
b)37/25:5/4:74/25=37/25*4/5*25/74=37*4*25/5*25*74=2/5.
c)380:(38*2)=(380:38):2=10:2=5.
d)6/11:4/3:5/11:4/3=6/11*3/4*11/5*3/4=6*3*11*3/11*4*5*4=27/40.
k nha
Tính bằng cách hợp lí:
a) \(\frac{15}{12}+\frac{5}{13}-\frac{3}{12}-\frac{18}{13}\) ( Phép này tính bằng 1 nhưng lại sai mất)
b) \(\frac{13}{25}+\frac{6}{41}-\frac{38}{25}+\frac{35}{41}-\frac{1}{2}\)
c) \(\left(\frac{1}{2}-\frac{2}{3}\right)-\left(\frac{5}{3}-\frac{3}{2}\right)+\left(\frac{7}{3}-\frac{5}{2}\right)\)
Help me!!!!! Nhanh nhé, 15' thui
\(a,=\left(\frac{15}{12}-\frac{3}{12}\right)+\left(\frac{5}{13}-\frac{18}{13}\right)\)
\(=1+-1\)
\(=0\)
\(a,\frac{-5}{14}-\frac{37}{14}\le x
Tính bằng cách thuận tiện:
a) 384:25:4 380: ( 38 x 2 )
b) \(\frac{37}{25}\):\(\frac{5}{4}\):\(\frac{74}{25}\) \(\frac{6}{11}\):\(\frac{4}{3}\):\(\frac{5}{11}\):\(\frac{4}{3}\)
a.384:25:4=384:[25x4]=384:100=3.84
380:[38x2]=[380:38]x2=20