\(\frac{1}{2}\cdot\frac{18}{14}+\frac{1}{2}\cdot\frac{3}{14}-\frac{1}{2}\cdot\frac{7}{14}\)
\(=\frac{1}{2}\left(\frac{18}{14}+\frac{3}{14}-\frac{7}{14}\right)\)
\(=\frac{1}{2}\cdot1=\frac{1}{2}\)
a) \(\dfrac{3}{7}\)+\(\dfrac{4}{9}\)+\(\dfrac{8}{14}\)+\(\dfrac{10}{18}\)
b) \(\dfrac{1}{2}\)x\(\dfrac{2}{3}\):\(\dfrac{5}{6}\)x\(\dfrac{5}{6}\)
bài này là bài tính bằng cách thuận tiện nhất nha !
Tính bằng cách thuận tiện nhất :
2/3 × 3/14+1/7×2/3+3/14×2
Tính bằng cách thuận tiện nhất
B=\(\dfrac{1+\dfrac{1}{7}+\dfrac{1}{7^2}-\dfrac{1}{7^3}}{4+\dfrac{4}{7}+\dfrac{4}{7^2}-\dfrac{4}{7^3}}x\dfrac{858585}{313131}x\left(-1\dfrac{14}{17}\right)\)
\(B=\dfrac{1+\dfrac{1}{7}+\dfrac{1}{7^2}-\dfrac{1}{7^3}}{4+\dfrac{4}{7}+\dfrac{4}{7^2}-\dfrac{4}{7^3}}\cdot\dfrac{858585}{313131}\cdot\left(-1\dfrac{14}{17}\right)\)
\(=\dfrac{1}{4}\cdot\dfrac{85}{31}\cdot\dfrac{-31}{17}\)
\(=\dfrac{-5}{4}\)
Ta có: \(B=\dfrac{1+\dfrac{1}{7}+\dfrac{1}{7^2}-\dfrac{1}{7^3}}{4+\dfrac{4}{7}+\dfrac{4}{7^2}-\dfrac{4}{7^3}}.\dfrac{858585}{313131}.\left(-1\dfrac{14}{17}\right)\)
\(=\dfrac{1+\dfrac{1}{7}+\dfrac{1}{7^2}-\dfrac{1}{7^3}}{4\left(1+\dfrac{1}{7}+\dfrac{1}{7^2}-\dfrac{1}{7^3}\right)}.\dfrac{85.10101}{32.10101}.\dfrac{-31}{17}=\dfrac{1}{4}.\dfrac{85}{31}.\dfrac{-31}{17}=-\dfrac{5}{4}\)
tính bằng cách thuận tiện nhất :
a) 52 x 2 + 48 x 2
b) 10 + 12 + 14 + 16 + 18 + 20
a) 52 x 2 + 48 x 2
= (52 + 48) x 2
= 100 x 2
= 200
b) 10 + 12 + 14 + 16 + 18 + 20
= (12 + 18) + (14 + 16) + (20 + 10)
= 30 + 30 + 30
= 90
Tính bằng cách thuận tiện
9/14 x 1+ 9/14=
\(\dfrac{9}{14}\times1+\dfrac{9}{14}\)
\(=\dfrac{9}{14}\times1+\dfrac{9}{14}\times1\)
\(=\dfrac{9}{14}\times\left(1+1\right)\)
\(=\dfrac{9}{14}\times2\)
\(=\dfrac{18}{14}=\dfrac{9}{7}\)
Tính bằng cách thuận tiện nhất :
37 x 18 - 9 x 14 + 100
15 x 2 + 15 x 3 + 15 x 5
52 + 37 + 48 + 63
37 x 18 - 9 x 14 + 100
=37*2*9-9*14+100
=74*9-9*14+100
=9*(74-14)+100
=9*60+100
=540+100
=640
15 x 2 + 15 x 3 + 15 x 5
=15*(2+3+5)
=15*10
=150
52 + 37 + 48 + 63
=(52+48)+(37+63)
=100+100
=200
37 x 18 - 9 x 14 + 100 = 37 x 2 x 9 - 9 x 14 + 100
= 74 x 9 - 9 x 14 + 100
= (74 - 14) x 9 +100
= 60 x 9 + 100
= 540 + 100
= 550
15 x 2 + 15 x 3 + 15 x 5 = 15 x ( 2 + 3 +5 )
= 15 x 10
= 150
52 + 37 + 48 + 63 = (52 + 48) + (37 + 63)
= 100 + 100
= 200
Duyệt!!!
37 x 18 - 9 x 14 + 100 = 37 x 2 x 9 - 9 x 14 + 100
= 74 x 9 - 9 x 14 + 100
= (74 - 14) x 9 +100
= 60 x 9 + 100
= 540 + 100
= 550
15 x 2 + 15 x 3 + 15 x 5 = 15 x ( 2 + 3 +5 )
= 15 x 10
= 150
52 + 37 + 48 + 63 = (52 + 48) + (37 + 63)
= 100 + 100
= 200
Tính bằng cách thuận tiện nhất:
a) 2070 + 414 x 4 x 28 - 138 x 3 x 17
b) 2020 x 14 + 4040 x 16 + 6060 x 18
c) 42 x 477 + 14 x 336 x 3 + 84 x 92 - 42
a) 2070 + 414 x 4 x 28 - 138 x 3 x 17 = 41400
b) 2020 x 14 + 4040 x 16 + 6060 x 18 = 72720
c) 42 x 477 + 14 x 336 x 3 + 84 x 92 - 42 = 41832
a) 2070 + 414 x 4 x 28 - 138 x 3 x 17 = 41400
b) 2020 x 14 + 4040 x 16 + 6060 x 18 = 72720
c) 42 x 477 + 14 x 336 x 3 + 84 x 92 - 42 = 41832
tính bằng cách thuận tiện nhất:
a.14/15 + 2/11 + 1/15 + 4/11 + 10/22 b.74 x 43 - 43 + 27 x 43
giúp mik đang cần gấp lắm
a. $\dfrac{14}{15}+\dfrac{2}{11}+\dfrac{1}{15}+\dfrac{4}{11}+\dfrac{10}{22}$
$=(\dfrac{14}{15}+dfrac{1}{15})+(\dfrac{2}{11}+\dfrac{4}{11}+\dfrac{10}{22})$
$=1+1=2$
b. $74\times43-43+27\times43$
$=(74-1+27)\times43$
$=100\times43=4300$
\(a)\dfrac{14}{15}+\dfrac{2}{11}+\dfrac{1}{15}+\dfrac{4}{11}+\dfrac{10}{22}\)
\(=\left(\dfrac{14}{15}+\dfrac{1}{15}\right)+\dfrac{2}{11}+\dfrac{4}{11}+\dfrac{5}{11}\)
\(=1+1=2\)
\(b)74\times43-43+27\times43\)
\(=43\times\left(74-1+27\right)\)
\(=43\times100=4300\)
a) \(\dfrac{14}{15}+\dfrac{2}{11}+\dfrac{1}{15}+\dfrac{4}{11}+\dfrac{10}{22}\)
= \(\left(\dfrac{14}{15}+\dfrac{1}{15}\right)+\left(\dfrac{2}{11}+\dfrac{4}{11}\right)+\dfrac{5}{11}\)
= \(1+\dfrac{6}{11}+\dfrac{5}{11}\)
= 2
b) 74 x 43 - 43 + 27 x 43
= 74 x 43 - 43 x 1 + 27 x 43
= 43 x ( 74 - 1 + 27 )
= 43 x 100
= 4300