Tính:
a)102+112+122/132+142
b)1.2.3...9-1.2.3...8-1.2.3...7.82
c)(3.4.216)2/11.213.411-169
d)1152-(374+1152)+(-65+374)
e)13-12+11+10-9+8-7-6+5-4+3+2-1
Giúp mình càng nhanh càng tốt nhé!!! Thank nhìu!
Bài 1 Tính nhanh
1.2.3...9-1.2.3...8-1.2.3...7.8.8
1152-(374+1152)+(-65+374)
13-12+11+10-9+8-7-6+5-4+3+2-1
Thuc hien cac phep tinh sau một cách hợp lí:
a) (10^2 + 11^2 + 12^2) : (13^2 + 14^2)
b) 1.2.3...9-1.2.3...8-1.2.3...7.8^2
c) (3.4.2^16)^2/11.2^13.4^11-16^9
d) 1152 - (374 + 1152) +(-65 + 374)
e) 13-12+11+10-9+8-7-6+5-4+3+2-1
thực hiện các phép tính sau một cách hợp lí:
a,\(\left(10^2+11^2+12^2\right):\left(13^2+14^2\right)\)
b,\(1.2.3...9-1.2.3...8-1.2.3...7.8^2\)
c,\(\frac{\left(3.4.2^{16}\right)^2}{11.2^{13}.4^{11}-16^9}\)
d,1152-(374+1152)+(-65+374)
e,13-12+11+10-9+8-7-6+5-4+3-2-1
a) =\(\left[\left(12+1\right)^2+\left(12+2\right)^2\right]:\left(13^2+14^2\right)\)
=1
b)=(1.2.3....8).(9-1-8)
=(1.2.3....8).0
=0
mik chỉ giải được zậy thôi.
t mik nha.
a)(10^2+11^2+12^2):(13^2+14^2) b)1.2.3...9-1.2.3...8-1.2.3...7.8^2 c)(3.4.2)^16/11.2^13.4^11-16^9 d)1152-(374+1152)+(-56+374) e)13-12+11+10-9+8-7-6+5-4+3+2-1 |
thực hiện các phép tính sau một cách hợp lí:
\(\left(10^2+11^2+12^2\right):\left(13^2+14^2\right)\)
1.2.3.....................9 - 1.2.3......8 - 1.2.3........7.\(^{8^2}\)
\(\frac{\left(3.4.2^{16}\right)^2}{11.2^{13}.4^{11}-16^9}\)
1152 - (374 + 1152 ) + (-65 + 374)
13 - 12 + 11 + 10 - 9 + 8 - 7 - 6 + 5 - 4 + 3 + 2 - 1
(10*2+11*2+12*2):(13*2+14*2)=100+121+144):(169+196)=1
a, \(\left(10^2+11^2+12^2\right)\div\left(13^2+14^2\right)\\ \)
b,\(1.2.3.....9-1.2.3....8-1.2.3.....7.8^2\)
c, \(\frac{\left(3.4.2^{16}\right)^2}{11.2^{13}.4^{11}-16^9}\)
d, \(1152-\left(374+1152\right)+\left(-65+374\right)\)
a) Đặt \(A=\left(10^2+11^2+12^2\right)\div\left(13^2+14^2\right)\)
- Ta có: \(A=\left(100+121+144\right)\div\left(169+196\right)\)
\(\Leftrightarrow A=365\div365=1\)
Vậy \(A=1\)
b) Đặt \(B=1.2.3.....9-1.2.3.....8-1.2.3.....8^2\)
- Ta có: \(B=1.2.3.....8.\left(9-1\right)-1.2.3.....8^2\)
\(\Leftrightarrow B=1.2.3.....8.8-1.2.3.....8.8=0\)
Vậy \(B=0\)
c) Đặt \(C=\frac{\left(3.4.2^{16}\right)^2}{11.2^{13}.4^{11}-16^9}\)
- Ta có: \(C=\frac{3^2.4^2.2^{32}}{11.2^{13}.2^{22}-2^{36}}\)
\(\Leftrightarrow C=\frac{3^2.2^4.2^{32}}{11.2^{35}-2^{36}}\)
\(\Leftrightarrow C=\frac{3^2.2^{36}}{2^{35}.\left(11-2\right)}\)
\(\Leftrightarrow C=\frac{9.2^{36}}{2^{35}.9}\)
\(\Leftrightarrow C=2\)
Vậy \(C=2\)
d) Đặt \(D=1152-\left(374+1152\right)+\left(-65+374\right)\)
- Ta có: \(D=1152-374-1152-65+374\)
\(\Leftrightarrow D=\left(1152-1152\right)+\left(374-374\right)-65\)
\(\Leftrightarrow D=-65\)
Vậy \(D=-65\)
tính nhanh
\(a,1+3-5-7+9+11-.....-397-399\)
\(b,1.2.3....9-1.2.3...8-1.2.3....7.8^2\)
\(c,1152-\left(374+1152\right)+\left(-65+344\right)\)
\(b,1.2.3...9-1.2.3...8-1.2.3...7.8^2\)
\(=(1.2.3...8).(9-1-8)\)
\(=(1.2.3...8).0\)
\(=0\)
a, 1 + 3 − 5 − 7 + 9 + 11 − ... − 397 − 399
= (1 + 3 - 5 - 7) + (9 + 11 - 13 - 15) + ... + (393 + 395 - 397 - 399)
= (-8) + (-8) + ... + (-8)
= (-8) . 50 (vì có 50 lần số hạng -8)
= - 400
_Vậy 1 + 3 − 5 − 7 + 9 + 11 − ... − 397 − 399 = -400
b, 1 . 2 . 3 ... 9 - 1 . 2 . 3 ... 8 - 1 . 2 . 3 ... 7 . 82
= (1 . 2 . 3 ... 8) (9 - 1 - 8)
= (1 . 2 . 3 ... 8) . 0
= 0
Bài 1: Thực hiện các phép tính sau một cách hợp lý:
a) ( 102 + 112 + 122 ) : ( 132 + 142 )
b) 1.2.3...9 - 1.2.3...8 - 1.2.3...7.82
c) ( 3.4.216)2 / 11.213.411-169
d) 1152 - ( 374 +1152 ) + ( -65+374 )
e) 13 - 12 +11 +10 - 9 + 8 - 7 - 6 + 5 - 4 + 3 + 2 - 1
Bài 2: Tìm x biết:
a) (19x + 2.52) :14 = (13 - 8)2 -42
b) x + ( x+1) + ( x+2) +...+ ( x+30) = 1240
c) 11 - (-53+x) = 97
d) -(x+84) +213 = -16
Bài 1:
A,
(100+121+144)÷(169+196)
=365:365=1
B
,1.2.3...7.8.(9-1-8)
=1.2.3...7.8.0=0
C,
3^2.2^4.2^32/11.2^13.2^22-2^26
=3^2.2^36/11.2^35-2^36
=3^2.2^36/2^35-(11-2)
=9.2/9=2
D,
=1152-374-1152+(-65)+374
=(1152-1152)+(-374+374)+(-65)
=0+0+(-65)=-65
E,
=13-(12-11-10+9)+(8-7-6+5)-(4-3-2+1)
=13-0+0-0=13
Bài 2:
A,(19x+50)÷14=25-16
(19x+50)÷14=9
19x+50=126
19x=76
x=4
B,
31x+(1+2+3+...+30)=1240
31x+465=1240
31x=775
×=25
BÀI 2:
c)11-(-53+x)=97
=> x=97-11-53
=> x=33
K CHO MÌNH NHA
Thực hiện các phép tính sau một cách hợp lý:
b) 1.2.3....9-1.2.3...8-1.2.3...7.\(8^2\)
c)\(\dfrac{\left(3.4.2^{16}\right)^2}{11.2^{13}.4^{11}-16^9}\)
d)\(1152-\left(374+1152\right)+\left(-65+374\right)\)
e)13-12+11+10-9+8\(-7-6+5-4+3+2-1\)
Trình bày lời giải đầy đủ giúp mk nha \(please\)
\(1.2.3...9-1.2.3...8-1.2.3...7.8^2\)
\(=\left(1.2.3...8\right).\left(9-1.8\right)\)
\(=\left(1.2.3...8\right).0\)
=0
d,\(1152-\left(374+1152\right)+\left(-65+374\right)\)
=1152-374-1152+(-65)+374
=(-1152+1152)+(-374+374)+(-65)
=0+0+(-65)
=0