a: =1037+743-(1031-57)
=1780-1031+57
=806
2: \(=\dfrac{125\cdot\left(-2\right)}{25\cdot\left(-2\right)}=5\)
3: \(=-25\cdot35-25\cdot147+35\cdot25+35\cdot147\)
\(=147\cdot10=1470\)
1037+{743-[1031-(+57)]}
(125.73-125.75):(-25.2)
-25.(35+147)+35.(25+147)
125.9.(-4).(-8).25.7
1037+{743-[1031-(+57)]}
(125.73-125.75):(-25.2)
-25.(35+147)+35.(25+147)
125.9.(-4).(-8).25.7
tính 1 cách hợp lí
A = - [ - 506 + 732 - ( -2000 ) ] - ( 506 - 1732 )
B = 1037 + { 743 - [ 1031 - ( + 57 )
Bài 1: Tính một cách hợp lí:
1) 2155 - ( 174 + 2155 ) + ( -68 + 174 ) 7) -1911 - ( 1234 - 1911 )
2) -25 . 72 + 25 . 21 - 49 . 25 8) 156 . 72 + 28 . 156
3) 35 . ( 14 - 23 ) - 23 . ( 14 - 35 ) 9) 32. ( -39 ) + 16 . ( -22 )
4) 8154 - ( 674 + 8154 ) + ( -98 + 674 ) 10) -1945 - ( 567 - 1945 )
5) -25 . 21 + 25 . 72 + 49 . 25 11) 184 . 33 + 67 . 184
6) 27 . ( 13 - 16 ) - 16 . ( 13 - 27) 12) 44 . ( -36 ) + 22 . ( -28 )
Tính:
1) 1996 . 1037 - 1996 . 37
2) (260 - 13) : 13
3) ( 23 . 35 + 35 . 37 ) : 60
Tính: \(\frac{3}{4}.\frac{8}{9}.\frac{15}{16}.\frac{24}{25}.\frac{35}{36}.\frac{48}{49}\)
Cho C= \(4+\dfrac{1}{7^6}+\dfrac{3}{7}+\dfrac{4}{7^2}+\dfrac{-441}{7^6}+\dfrac{27}{7^5}\)
D= \(\dfrac{147}{7^3}+4+\dfrac{35}{7^7}+\dfrac{4}{7^2}+\dfrac{27}{7^5}+\dfrac{-9}{7^9}\)
So sánh C với D
Bỏ ngoặc rồi tính :
a, - ( - 15 + 125 - 81 ) - ( - 85 + 75 - 19 + 100 )
b, ( 39 - 48 + 57 ) - ( - 61 + 52 + 157 )
c, ( -25 - 65 + 30 ) - ( 75 - 65 - 170 )
d, - ( - 45 - 135 + 29 ) + ( 55 - 35 - 71 )
1 . Tính nhanh
a/ 15 . ( 27 + 18 + 6 ) + 15 . ( 23 + 12 )
b/ 14 . 35 . 5 + 10 . 25 .7 + 20 . 70
c/ 53 . ( 51 + 4 ) + 53 . ( 49 + 96 ) + 53
d/ 46 . ( 27 + 75 ) + 8 . ( 58 + 25 ) . 2
