Tính nhanh 54*450+18*126*3+848*27
tính nhanh
1*3*9+2*6*18+3*9*27/1*5*18+2*10*36+3*15*54
\(\frac{1\cdot3\cdot9+2\cdot6\cdot18+3\cdot9\cdot27}{1\cdot5\cdot18+2\cdot10\cdot36+3\cdot15\cdot54}\)
\(=\frac{1\cdot3\cdot9+2\left(1\cdot3\cdot9\right)+3\left(1\cdot3\cdot9\right)}{1\cdot5\cdot18+2\left(1\cdot5\cdot18\right)+3\left(1\cdot5\cdot18\right)}\)
\(=\frac{\left(1\cdot3\cdot9\right)\left(1+2+3\right)}{\left(1\cdot5\cdot18\right)\left(1+2+3\right)}\)
\(=\frac{3}{10}\)
tính nhanh:
45+27+65+46+35+73+54+18+27
Đề:45+27+65+46+35+73+54+18+27
=(27+73)+(65+35)+(54+46)+(45+27+18)
=100+100+100+90
=390
214 x 300= 24:3-15:3=
126 x 360= 63:9-36:9=
130 x 293= {54+27}:9=
10 người đâu giải nhanh em tick cho
tính nhanh :
2/9 + 6/27 + 8/36 +12/54 + 16/72 + 18/81
a)TÍNH BẰNG CÁCH THUẬN TIỆN
123 x 54 + 27 x 123 - 12 x 123 + 123 x 31
b)TÌM n
121/27 x 54/11 < n < 100/21 : 25/126
\(a,123\times54+27\times123-12\times123+123\times31\)
\(=123\times\left(54+27-12+31\right)\)
\(=123\times100\)
\(=12300\)
\(b,\dfrac{121}{27}\times\dfrac{54}{11}< n< \dfrac{100}{21}:\dfrac{25}{126}\)
\(22< n< \dfrac{100}{21}\times\dfrac{126}{25}\)
\(22< n< 24\)
Vì \(23>22\) và \(23< 24\) nên \(n=23\)
a, 123x(54+27-12+31)
=123x100
=12300
a)TÍNH BẰNG CÁCH THUẬN TIỆN
123 x 54 + 27 x 123 - 12 x 123 + 123 x 31
b)TÌM n
121/27 x 54/11 < n < 100/21 : 25/126
a123x54+27x123-12x123+123x31
=123:54+27:123-12:123+123:31
=6642+27:123-12:123+123:31
=6642+3321-12:123+123:31
=6642+3321-1476+123:31
=6642+3321-1476+3813
=12300
b,121/27x54/11<n>100/21:25/126
=22<n>24
n=23
TÍNH NHANH
A, 54*14-54*53+14*146-53*44
B,2^8*510-128*128
C,18^6*2^12*4^3*9^3 : 16^3*6^9*27^3
1 Tìm số tự nhiên sao cho:
121/27 x 54/11< n < 100/21 : 25/126
2 Tính nhanh:
(m:1-m x 1) : (m x 2005 + m +1)
bài 1"
121/27 x 54/11 < n < 100/21 : 25/126
=> 22 < n < 24
mà n là số tự nhiên
=> n = 23
Bài 2:
(m:1 - m x 1) : ( m x 2005 + m + 1)
= (m-m) : ( m x 2005 + m + 1)
= 0 : (m x 2005 + m + 1) = 0
1.
\(\frac{121}{27}\times\frac{54}{11}< n< \frac{100}{21}:\frac{25}{126}\)
=> \(22< n< 24\)
Mà n là số tự nhiên
=> n = 23
2.
( m : 1 + m x 1 ) : ( m x 2005 + m + 1 )
= ( m - m ) : ( m x 2005 + m + 1 )
= 0 : ( m x 2005 + m + 1 )
= 0
Tính nhanh tổng sau:
2/9 + 6/27 + 8/36 + 12/54 + 16/72 + 18/81
2/9 + 6/27 + 8/36 + 12/54 + 16/72 + 18/81=\(\frac{2}{9}+\frac{2}{9}+\frac{2}{9}+\frac{2}{9}+\frac{2}{9}+\frac{2}{9}\) = \(\frac{2}{9}\). 6 = \(\frac{12}{9}\)= \(\frac{4}{3}\)
\(\frac{2}{9}+\frac{6}{27}+\frac{8}{36}+\frac{12}{54}+\frac{16}{72}+\frac{18}{81}\)
\(=\frac{2}{9}+\frac{2}{9}+\frac{2}{9}+\frac{2}{9}+\frac{2}{9}+\frac{2}{9}\)
\(=\frac{2}{9}×6=\frac{4}{3}\)