Tính nhanh (56.46-25.23):23
1) 33.18+72.42 - 41.18
2) (56.46 - 25.23 ) : 23
3) (76 . 34 - 19 .64 ) : (38.9)
4) (5.411 - 3. 165 ) : 410
5) ( 28.54 + 56.36 ) :21:2
Tính nhanh nếu có thể
1)
33 . 18 + 72 . 42 - 41 . 18
= 33 . 18 + 18 . 43 - 41 . 18
= 18 . ( 33 + 43 - 41 )
= 18 . 50
= 900
2) ( 56 . 46 - 25 . 23 ) : 23
= ( 112 . 23 - 25 . 23 ) : 23
= ( 112 - 25 ) . 23 : 23
= 87 . 23 : 23
= 87
3) ( 76 . 34 - 19 . 64 ) : ( 38 . 9 )
= ( 19 . 136 - 19 . 64 ) : ( 19 . 18 )
= 19 . ( 136 - 64 ) : ( 19 . 18 )
= 19 . 72 : 19 . 18
= 19 . 4
= 76
4) ( 5 . 411 - 3 . 165 ) : 410
= ( 5 . 411 - 3 . 410 ) : 410
= ( 20 . 410 - 3 . 410 ) : 410
= ( 20 - 3 ) . 410 : 410
= 17
bài 1: thực hiện phép tính: (tính nhanh nếu có thể)
a,347.2^2.9(216+184):8
b,132-Ơ116-(132-128)^2}
c,16:{400:[200-(37+46.3)]}
d,{184:[96-124:31]-2}.3651
e,46-[(16+71.4):15]-2
f,3^3.18+72.4^2-41.18
g,(56.46-25.23):23
h,(28.54+56.36):21:2
i,(76.34-19.64):(38.9)
k,(2+4+6+...+100).(36.333-108.111)
m,(5.4^11-3.16^5):4^10
n,7256.4375-725
______________
3650+4375.7255
a: \(=347\cdot4\cdot9\cdot400:8=347\cdot36\cdot50=624600\)
c: \(=16:\left\{400:\left[200-37-138\right]\right\}\)
\(=16:\left\{400:25\right\}=16:16=1\)
e: \(=46-\left[300:15\right]-2=46-20-2=24\)
1/ 33.18+72.42-41.18 4/ (2+4+6+......+100).(36.333-108.111)
2/ (56.46-25.23):23 5/ (5.411-3.165):410
3/ (28.54+56.36):21:2
3^3.18+72.4^2-41.18=27.18+18.64-41.18=18(27+64-41)=18.50=900
(56.46-25.23);23=(112.23-25.23):23=87.23:23=87
(28.54+56.36):21:2=(28.54+28.72):21:2=28.126:21:2=(28:2).(126:21)=14.6=84
(2+4+6+....+100)(36.333-108.111)=(2+4+6+100)(108.111-108.111)=0
(5.4^11-3.16^5):4^10=(5.4^11-3.4^10):4^10=5.4-3=17
tính bằng cách hợp lý
(217+172).(915-315).(24-42)
(71997-71995):(71994.7)
(12+23+34+45).(13+23+3343).(38-812)
(28+83):(25.23)
\(\left(2^{17}+7^2\right).\left(9^{15}-3^{15}\right).\left(2^4-4^2\right)\)
\(=\left(2^{17}+7^2\right).\left(9^{15}-3^{15}\right).\left(16-16\right)\)
\(=\left(2^{17}+7^2\right).\left(9^{15}-3^{15}\right).0\)
\(=0\)
-------------------------------------------------
\(\left(7^{1997}-7^{1995}\right):\left(7^{1994}.7\right)\)
\(=\left[7^{1995}\left(7^2-1\right)\right]:7^{1995}\)
\(=7^{1995}.48:7^{1995}\)
\(=48\)
-------------------------------------------------
\(\left(1^2+2^3+3^4+4^5\right).\left(1^3+2^3+3^3+4^3\right).\left(3^8-81^2\right)\)
\(=\left(1^2+2^3+3^4+4^5\right).\left(1^3+2^3+3^3+4^3\right).\left(6561-6561\right)\)
\(=\left(1^2+2^3+3^4+4^5\right).\left(1^3+2^3+3^3+4^3\right).0\)
\(=0\)
-------------------------------------------------
\(\left(2^8+8^3\right):\left(2^5.2^3\right)\)
\(=\left[2^8+\left(2^3\right)^3\right]:2^8\)
\(=\left(2^8+2^9\right):2^8\)
\(=2^8.\left(1+2\right):2^8\)
\(=2^8.3:2^8\)
\(=3\)
\((2^{17}+17^{2}).(9^{15}-3^{15}).(2^{4}-4^{2})\)
\(=(2^{17}+17^{2}).(9^{15}-3^{15}).(16-16)\)
\(=(2^{17}+17^{2}).(9^{15}-3^{15}).0\)
\(=0\)
\((7^{1997}-7^{1995}):(7^{1994}.7)\)
\(=(7^{1997}-7^{1995}):7^{1995}\)
\(=7^{1997}:7^{1995}-7^{1995}:7^{1995}\)
\(=7^{2}-1=49-1=48\)
\(1^{2}+2^{3}+3^{4}+4^{5}).(1^{3}+2^{3}+3^{3}+4^{3}).(3^{8}-81^{2})\)
\(=(1^{2}+2^{3}+3^{4}+4^{5}).(1^{3}+2^{3}+3^{3}+4^{3}).(6561-6561)\)
\(=(1^{2}+2^{3}+3^{4}+4^{5}).(1^{3}+2^{3}+3^{3}+4^{3}).0\)
\(=0\)
\((2^{8}+8^{3}):(2^{5}.2^{3})\)
\(=[2^{8}+(2^{3})^{3}]:2^{8}\)
\(=(2^{8}+2^{9}):2^{8}\)
\(=2^{8}:2^{8}+2^{9}:2^{8}\)
\(=1+2=3\)
Bài toán 4: Thực hiện các phép tính sau bằng cách hợp lý.
a) (217+ 172).(915– 315).(24 – 42)
b) (82017– 82015) : (82104.8)
c) (13+ 23+ 34 + 45).(13 + 23 + 33 + 43).(38 – 812)
d) (28+ 83) : (25.23)
a: Ta có: \(\left(2^{17}+17^2\right)\cdot\left(9^{15}-3^{15}\right)\cdot\left(2^4-4^2\right)\)
\(=\left(2^{17}+17^2\right)\cdot\left(9^{15}-3^{15}\right)\cdot\left(16-16\right)\)
=0
b: Ta có: \(\dfrac{8^{2017}-8^{2015}}{8^{2104}\cdot8}\)
\(=\dfrac{8^{2015}\cdot\left(8^2-1\right)}{8^{2105}}\)
\(=\dfrac{1\cdot63}{8^{90}}\)+
c: Ta có: \(\left(1^3+2^3+3^4+4^5\right)\cdot\left(1^3+2^3+3^3+4^3\right)\cdot\left(3^8-81^2\right)\)
\(=\left(1^3+2^3+3^4+4^5\right)\cdot\left(1^3+2^3+3^3+4^3\right)\cdot\left(3^8-3^8\right)\)
=0
d: Ta có: \(\left(2^8+8^3\right):\left(2^5\cdot2^3\right)\)
\(=\dfrac{2^8+2^9}{2^8}\)
=3
làm hộ mình với
tính nhanh
25.23+25.77
Bài toán : Thực hiện các phép tính sau bằng cách hợp lý.
a. (217 + 172)x(915 – 315)x(24 – 42)
b. (82017 – 82015) : (82104.8)
c. (13 + 23 + 34 + 45).(13 + 23 + 33 + 43).(38 – 812)
d. (28 + 83) : (25.23)
Thực hiện phép tính :
a) \(80-\left(4.5^2-3.2^3\right)\)
b) \(23.75+25.23+180\)
c) \(2448:\left[119-\left(23-6\right)\right]\)
a) 80 - (4.52 - 3.23)
= 80 - 100 + 24
= 4
b) 23.75 + 25.23 + 180
= 25.(23.3 + 23) + 180
= 25.23.4 + 180
= 100.23 + 180
= 2300 + 180
= 2480
c) 2448 : [119 - (23 - 6)]
= 2448 : (119 - 17)
= 2448 : 102
= 24
a,80 - (100-24)
= 80-76
= 4
b,1725+575+180
=2300+180
=2480
c,2448 : [119-17]
=2448 : 102
= 24
mik mong bn sẽ làm đúng
80-(4.52-3.23) 23.75+25.23+180
2448:[119-(23-6)]
a, = 80-(4.25-3.8)
= 80 - ( 100 - 24 )
= 80 - 76
= 4
b , 23,75+25,23+180 = 48.98 + 180 = 228.98
c , 2448 : [119 - ( 23 - 6 ) = 2448 : [ 119 - 17 ]
= 2448 : 7
= 394.7142857
a, = 80-(4.25-3.8)
= 80 - ( 100 - 24 )
= 80 - 76
= 4
b , 23,75+25,23+180
= 48.98 + 180 = 228.98
c , 2448 : [119 - ( 23 - 6 ) = 2448 : [ 119 - 17 ]
= 2448:7
= 394.7142857
tick nhé bạn
a, = 80-(4.25-3.8)
= 80 - ( 100 - 24 )
= 80 - 76
= 4
b , 23,75+25,23+180 = 48.98 + 180 = 228.98
c , 2448 : [119 - ( 23 - 6 ) = 2448 : [ 119 - 17 ]
= 2448 : 7
= 394.7142857