4.8 ✖ 8 ➕ 6 ✖ 4.8 ➖ 8 ✖ 2.4
12,5 ✖ 15,32 ✖ 0,008 ➕ 15,32 ✖ 0,9
Tính nhanh
cho đề rõ hơn đi e
( 1 - \(\dfrac{1}{2}\) ) ✖ ( 1 - \(\dfrac{1}{3}\) ) ✖ ( 1 - \(\dfrac{1}{4}\) ) ✖ ( 1 - \(\dfrac{1}{5}\) ) ✖ ( 1 - \(\dfrac{1}{6}\) ) ✖ ( 1 - \(\dfrac{1}{7}\) ) ✖ (1 - \(\dfrac{1}{8}\))
\(=\dfrac{1}{2}\cdot\dfrac{2}{3}\cdot...\cdot\dfrac{7}{8}=\dfrac{1}{8}\)
`= 1/2 xx 2/3 xx...xx 7/8`
`= 1/8`
\(=\dfrac{1}{2}\times\dfrac{2}{3}\times\dfrac{3}{4}\times...\times\dfrac{6}{7}\times\dfrac{7}{8}\\ =\dfrac{1}{8}\)
Tính nhanh
A, 325+612+675+388
B, 268 ✖ 8+315 ✖ 33+315
C, 315 ✖ 66+315 ✖ 33+325
D, 2017 ✖ 19-2017 ✖ 8-2017
E, 3150-267-315-733-685
A) 325 + 612 + 675 + 388
= ( 325 + 612 ) + ( 675 + 388 )
= 937 + 1063
= 2000
B) 268 x 8 + 315 x 33 + 315
= ( 268 x 8 ) + ( 315 x 33 ) + 315
= 2144 + 10395 + 315
= 12539 + 315
= 12854
C) 315 x 66 + 315 x 33 + 325
= ( 315 x 66 ) + ( 315 x 33 ) + 325
= 20790 + 10395 + 325
= 31185 + 325
= 31510
D) 2017 x 19 - 2017 x 8 - 2017
= ( 2017 x 19 ) - ( 2017 x 8 ) - 2017
=38323 - 16136 -2017
= 22187 - 2017
= 20170
E) 3150 - 267 - 315 - 733 - 685
= ( 3150 - 267 ) - 315 - ( 733 - 685 )
= 2883 - 315 - 48
= 2568 - 48
= 2520
6✖113✖3✖113✖113
2.8 phút ✖ 6=..........phút.... . giây
2 giờ 45 phút ✖ 8:2=.............
Nhanh lên nhé
2,8 phút x 6=16 phút 48 giây
2 giờ 45 phút x 8:2=11 giờ
Photocopy xong nhớ đúng đấy!
B=(1-\(\dfrac{1}{3}\)) ✖(1-\(\dfrac{1}{6}\))✖(1-\(\dfrac{1}{10}\))✖(1-\(\dfrac{1}{15}\))✖....✖(1-\(\dfrac{1}{780}\))
\(B=\left(1-\dfrac{1}{3}\right)\cdot\left(1-\dfrac{1}{6}\right)\cdot\left(1-\dfrac{1}{10}\right)\cdot\left(1-\dfrac{1}{15}\right)\cdot...\cdot\left(1-\dfrac{1}{780}\right)\)
\(B=\left(1-\dfrac{1}{3+6+10+15+...+780}\right)\)
\(B=\left(1-\dfrac{1}{\left(780-3\right)\div3+1}\right)\)
\(B=\left(1-\dfrac{1}{260}\right)\)
\(B=\dfrac{259}{260}\)
\(\dfrac{-5}{13}\)✖\(\dfrac{3}{7}\)-\(\dfrac{2}{17}\)✖\(\dfrac{8}{13}\)+\(\dfrac{5}{13}\)✖\(\dfrac{1}{7}\)
Giải hộ mình nhé có cả lời giải đấy
ok.mình cho 1 tim
Ta có: \(\dfrac{-5}{13}\cdot\dfrac{3}{7}-\dfrac{2}{17}\cdot\dfrac{8}{13}+\dfrac{5}{13}\cdot\dfrac{1}{7}\)
\(=\dfrac{5}{13}\left(-\dfrac{3}{7}+\dfrac{1}{7}\right)-\dfrac{2}{17}\cdot\dfrac{8}{13}\)
\(=\dfrac{5}{13}\cdot\dfrac{-2}{7}-\dfrac{2}{17}\cdot\dfrac{8}{13}\)
\(=\dfrac{-10}{91}-\dfrac{16}{221}\)
\(=\dfrac{-282}{1547}\)
\(\dfrac{-5}{13}.\dfrac{3}{7}-\dfrac{2}{17}.\dfrac{8}{13}+\dfrac{5}{13}.\dfrac{1}{7}\)
\(=\dfrac{5}{13}.\dfrac{-3}{7}-\dfrac{2}{17}.\dfrac{8}{13}+\dfrac{5}{13}.\dfrac{1}{7}\)
\(=\dfrac{5}{13}.\left(\dfrac{-3}{7}+\dfrac{1}{7}\right)+\dfrac{-2}{17}.\dfrac{8}{13}\)
\(=\dfrac{5}{13}.\dfrac{-2}{7}+\dfrac{-2}{13}.\dfrac{8}{17}\)
\(=\dfrac{-2}{13}.\dfrac{5}{7}+\dfrac{-2}{13}.\dfrac{8}{17}\)
\(=\dfrac{-2}{13}.\left(\dfrac{5}{7}+\dfrac{8}{17}\right)\)
\(=\dfrac{-2}{13}.\dfrac{141}{119}\)
\(=\dfrac{-282}{1547}\)
Tính giá trị biểu thức bằng cách thuận tiện nhất
5,26 ✖ 2 + 2,63 ✖ 8 + 5,26 : 0,25
Tính giá trị biểu thức bằng cách thuận tiện nhất
5,26 ✖ 2 + 2,63 ✖ 8 + 5,26 : 0,25