tính nhanh:
98.28-(184-1)(184+1)
98.28- (184-1)(184+1)
98.28-(184-1)(184+1)
=98.28-\(184^2\)+1
=2744-33856 +1
=-31111
98.28-(184-1)(184+1)
98.28-(184-1)(184+1)
=2744-183.185
=2744-33855
=-31111
Tính nhanh :
a) 1272+146.127+732
b) 98.28-(184-1)(184+1)
c) \(\frac{180^2-220^2}{125^2+150.125+75^2}\)
tính nhanh
a)1272+146.127+732
b)98.28-(184-1)(184+1)
c)1802-2202/1252+150.125+752
Bài 1:
a) 1042 - 16
b) 98.28 - (184 - 1)(184 + 1)
c) 9993 +3.9992 + 3.999 + 1
d) 423 - 6.422 + 12.42 - 8
Bài 2:
a) x(x - 2012) - 2013x +2012.2013 = 0
b) (x - 1)3 + 1 + 3x(x - 4) = 0
c) (x + 4)2 - 16 = 0
\(Bài.1:\\ a,104^2-16=104^2-4^2=\left(104+4\right)\left(104-4\right)=108.100=10800\\ b,9^8.2^8-\left(18^4-1\right)\left(18^4+1\right)\\ =\left(9.2\right)^8-\left(18^8-1\right)=18^8-18^8+1=1\\ c,999^3+3.999^2+3.999+1\\ =999^3+3.999^2.1+3.999.1^2+1^3=\left(999+1\right)^3=1000^3=1000000000\\ d,42^3-6.42^2+12.42-8\\ =42^3-3.42^2.2+3.42.2^2-2^3\\ =\left(42-2\right)^3=40^3=64000\)
Bài 1
a) 104² - 16
= 104² - 4²
= (104 - 4)(104 + 4)
= 100.108
= 10800
b) 9⁸.2⁸ - (18⁴ - 1)(18⁴ + 1)
= 18⁸ - (18⁸ - 1)
= 18⁸ - 18⁸ + 1
= 1
c) 999³ + 3.999² + 3.999 + 1
= (999 + 1)³
= 1000³
= 1000000000
d) 42³ - 6.42² + 12.42 - 8
= (42 - 2)³
= 40³
= 64000
Bài 2
a) x(x - 2012) - 2013x + 2012.2013 = 0
⇔ x(x - 2012) - 2013(x - 2012) = 0
⇔ (x - 2012)(x - 2013) = 0
⇔ x - 2012 = 0 hoặc x - 2013 = 0
*) x - 2012 = 0
⇔ x = 2012
*) x - 2013 = 0
⇔ x = 2013
Vậy x = 2012; x = 2013
b) (x - 1)³ + 1 + 3x(x - 4) = 0
⇔ x³ - 3x² + 3x - 1 + 1 + 3x² - 12x = 0
⇔ x³ - 9x = 0
⇔ x(x² - 9) = 0
⇔ x(x - 3)(x + 3) = 0
⇔ x = 0 hoặc x - 3 = 0 hoặc x + 3 = 0
*) x - 3 = 0
⇔ x = 3
*) x + 3 = 0
⇔ x = -3
Vậy x = -3; x = 0; x = 3
c) (x + 4)² - 16 = 0
⇔ (x + 4)² - 4² = 0
⇔ (x + 4 - 4)(x + 4 + 4) = 0x
⇔ (x + 8) = 0
⇔ x = 0 hoặc x + 8 = 0
*) x + 8 = 0
⇔ x = -8
Vậy x = -8; x = 0
Tính nhanh
a) 1272 + 146x127 + 732
b) 98x28 - (184-1)x(184+1)
Thực hiện phép tính: (Tính nhanh nếu có thể)
1) 347.22 – 22 . ( 216 + 184 ) : 8 ;
2) 132 – [116 – ( 132 – 128 )2] ;
3) 16 :{400 : [200 – ( 37 + 46 . 3 )]} ;
4) {184 : [96 – 124 : 31 ] – 2 }. 3651 ;
5) 46 – [ (16 + 71 . 4 ) : 15 ]} – 2 ;
6) 33.18 + 72 .42 – 41 .18
7)( 56 . 46 – 25 . 23 ) : 23 ;
8) ( 28 . 54 + 56 . 36 ) : 21 : 2 ;
9) ( 76 . 34 – 19 . 64 ) : ( 38 . 9 ) ;
10) ( 2+ 4 + 6 + ….. + 100 ) . ( 36 . 333 – 108 . 111)
11) ( 5 . 411- 3 .165 ): 410
12) \(\dfrac{7256.4375-725}{3650+4375.7255}\)
Tính nhanh :
a) 1272 + 146 . 127 + 732
b) 98 . 28 - (184 - 1)(184+1)
c) 1002 - 992 + 982 - 982 + ... + 22 - 12
d) (202 + 182 + 162 + ... + 42 + 22) - (192 + 172 + ... + 32 + 12)
a) \(=\left(127+73\right)^2=200^2=40000\)
b) \(=18^8-\left(18^8-1\right)=1\)
c) \(=\left(100+99\right)\left(100-99\right)+\left(98+97\right)\left(98-97\right)+...+\left(2+1\right)\left(2-1\right)\)
\(=100+99+98+97+...+2+1=5050\)
d) biến đổi thành \(20^2-19^2+18^2-17^2+..+2^2-1^2\)
rồi giải ra như trên
Thực hiện phép tính: (Tính nhanh nếu có thế)
1) 347.222-222.(216+184):8
2) 132-[116-(132-128)22]
3) 16:{400:[200-(37+46.3)]}
4) {184:[96-124:31]-2}.3651
5) ) 46 – [ (16 + 71 . 4 ) : 15 ]} – 2
6) 33.18 + 72 .42 – 41 .18
7)( 56 . 46 – 25 . 23 ) : 23
8) ( 28 . 54 + 56 . 36 ) : 21 : 2
9) ( 76 . 34 – 19 . 64 ) : ( 38 . 9 )
10) ( 2+ 4 + 6 + ….. + 100 ) . ( 36 . 333 – 108 . 111)
11) ( 5 . 411- 3 .165 ): 410
12) 7256.4375−725/3650+4375.7255
Giải;
1) \(347.222-222.\left(216+184\right):8\)
\(=347.222-222.400:8\)
\(=347.222-222.50\)
\(=222.\left(347-50\right)\)
\(=222.297\)
\(=65934\)
2) \(132-\left[116-\left(132-128\right).22\right]\)
\(=132-\left[116-4.22\right]\)
\(=132-\left[116-88\right]\)
\(=132-28\)
\(=104\)
3) \(16:\left\{400:\left[200-\left(37+46.3\right)\right]\right\}\)
\(=16:\left\{400:\left[200-\left(37+138\right)\right]\right\}\)
\(=16:\left\{400:\left[200-175\right]\right\}\)
\(=16:\left\{400:25\right\}\)
\(=16:16\)
\(=1\)
4) \(\left\{184:\left[96-124:31\right]-2\right\}.3651\)
\(=\left\{184:\left[96-4\right]-2\right\}.3651\)
\(=\left\{184:92-2\right\}.3651\)
\(=\left\{2-2\right\}.3651\)
\(=0.3651\)
\(=0\)
5) \(46-\left[\left(16+71.4\right):15\right]-2\)
\(=46-\left[\left(16+284\right):15\right]-2\)
\(=46-\left[300:15\right]-2\)
\(=46-20-2\)
\(=24\)
6) \(3^3.18+72.4^2-41.18\)
\(=18.\left(27-41\right)+72.16\)
\(=18.-14+1152\)
\(=-252+1152\)
\(=900\)
Giải: (tiếp)
7) \(\left(56.46-25.23\right):23\)
\(=\left(2576-575\right):23\)
\(=2001:23\)
\(=87\)
8) \(\left(28.54+56.36\right):21:2\)
\(=\left(1512+2016\right):21:2\)
\(=3528:21:2\)
\(=84\)
9) \(\left(76.34-19.64\right):\left(38.9\right)\)
\(=\left(2584-1216\right):342\)
\(=1368:342\)
\(=4\)
10) \(\left(2+4+6+...+100\right).\left(36.333-108.111\right)\)
\(=\left(2+4+6+...+100\right).\left(11988-11988\right)\)
\(=\left(2+4+6+...+100\right).0\)
\(=0\)
11) \(\left(5.4^{11}-3.16^5\right):4^{10}\)
\(=5.4^{11}:4^{10}-3.16^5:4^{10}\)
\(=5.4-3.1\)
\(=20-3\)
\(=17\)
12) \(7256.4375-725:3650+4375.7255\)
\(=4375.\left(7256+7255\right)-\dfrac{29}{146}\)
\(=4375.14511-\dfrac{29}{146}\)
\(=63485624,8\)
Câu 12 ko chắc!
Thực hiện phép tính: (Tính nhanh nếu có thế)
1) 347.2\(^2\)-2\(^2\).(216+184):8
2) 132-[116-(132-128)\(^2\)]
3) 16:{400:[200-(37+46.3)]}
4) {184:[96-124:31]-2}.3651
5) ) 46 – [ (16 + 71 . 4 ) : 15 ]} – 2
6) 33.18 + 72 .42 – 41 .18
7)( 56 . 46 – 25 . 23 ) : 23
8) ( 28 . 54 + 56 . 36 ) : 21 : 2
9) ( 76 . 34 – 19 . 64 ) : ( 38 . 9 )
10) ( 2+ 4 + 6 + ….. + 100 ) . ( 36 . 333 – 108 . 111)
11) ( 5 . 411- 3 .165 ): 410
12) \(\dfrac{7256.4375-725}{3650+4375.7255}\)