tính nhanh :
A= 127^2+46.127+73^2
Tính nhanh
A=20^2+18^2+16^2+.....+2^2-19^2-17^2-3^2-1
B=127^2+146×127+73^2
Tính nhanh
( - 127 ) x 73 + 127 x ( -27 )
(-127) x 73+(-127) x 27
=(-127) . (73+27)
=(-127).100
=-12700
1,tính nhanh giá trị các biểu thức sau
a , C= 1272 + 146 . 127 + 732
b, A = \(\frac{2006^3+1}{2006^2-2005}\) ; B =\(\frac{2006^3-1}{2006^2+2007}\)
ai nhanh mik tik cho
a, \(C=127^2+146.127+73^2\)
\(=127^2+2.127.73+73^2\)
\(=\left(127+73\right)^2\)
\(=200^2=40000\)
a, \(\frac{2006^3+1}{2006^2-2005}\)
\(=\frac{\left(2006+1\right)\left(2006^2-2006+1\right)}{2006^2-2005}=\frac{2007\left(2006^2-2005\right)}{2006^2-2005}=2007\)
\(\frac{2006^3-1}{2006^2+2007}\)
\(=\frac{\left(2006-1\right)\left(2006^2+2006+1\right)}{2006^2+2007}=\frac{2005\left(2006^2+2007\right)}{2006^2+2007}=2005\)
Chúc bạn học tốt.
Tính Nhanh
A= 1995^2 -1994.1996
B= 9^8.2^8-(18^4-1).(18^4+1)
C=163^2+74.163+37^2
D=127^2+146.127+73^2
MẤY BẠN GIÚP MÌNH VỚI MÌNH CẦN GẤP LẮM
A = 19952 - ( 1995-1) (1995+1)
= 19952 - (19952 - 12)
= 19952 - 19952 +1
= 1
Tính nhanh:
a. 79 + 243 + 21
b. 127 + 760 + 73 + 40
c.73 + 86 + 968 + 914 + 3032
d. 40 + 41 + 42 + ... + 50
e. 1 + 2 + 3 + 4 + 5 ... + 200
e) \(1+2+3+...+200\)
\(=\frac{\left(200+1\right).\left[\left(200-1\right)+1\right]}{2}\)
\(=20100\)
\(a)79+243+21\)
\(=\left(79+21\right)+243\)
\(=100+243\)
\(=343\)
a) 79 + 243 + 21
= 343
b) 127 + 760 + 73 + 40
= 1000
c) 73 + 86 + 968 + 914 + 3032
= 5073
d) 40 + 41 + ...+50
= 495
e) 1 + 2 + 3 + ... + 50
= 1275.
Tính nhanh, dùng hằng đẳng thức thứ 1;2;3
a) 1272 + 146 . 127 + 732
b) 98 . 28 - (184 - 1)(184 + 1)
c) \(\frac{780^2-220^2}{125^2+150.125+75^2}\)
a) 1272 + 146.127 + 732
= 1272 + 2.73.127 + 732
= (127 + 73)2 = 2002 = 40000
b) 98 . 28 - (184 - 1)(184 + 1)
= (9.2)8 - 188 + 1
= 188 - 188 + 1 = 1
c) \(\frac{780^2-220^2}{125^2+150.125+75^2}=\frac{\left(780-220\right)\left(780+220\right)}{125^2+2.75.125+75^2}=\frac{560.1000}{\left(125+75\right)^2}=\frac{560000}{200^2}\)
\(=\frac{560000}{40000}=14\)
a) 1272 + 146.127 + 732
= 1272 + 2.73.127 + 732
= ( 127 + 73 )2
= 2002 = 40 000
b) 98.28 - ( 184 - 1 )( 184 + 1 )
= ( 9.2 )8 - [ ( 184 )2 - 12 ]
= 188 - 188 + 1
= 1
c) \(\frac{780^2-220^2}{125^2+150\cdot125+75^2}\)
\(=\frac{\left(780-220\right)\left(780+220\right)}{125^2+2\cdot75\cdot125+75^2}\)
\(=\frac{560\cdot1000}{\left(125+75\right)^2}\)
\(=\frac{560000}{200^2}\)
\(=\frac{560000}{40000}=14\)
Bài làm :
a) 1272 + 146.127 + 732
= 1272 + 2.73.127 + 732
= ( 127 + 73 )2
= 2002
= 40 000
b) 98.28 - ( 184 - 1 )( 184 + 1 )
= ( 9.2 )8 - [ ( 184 )2 - 12 ]
= 188 - 188 + 1
= 1
\(\text{c)}\frac{780^2-220^2}{125^2+150\cdot125+75^2}\)
\(=\frac{\left(780-220\right)\left(780+220\right)}{125^2+2\cdot75\cdot125+75^2}\)
\(=\frac{560\cdot1000}{\left(125+75\right)^2}\)
\(=\frac{560000}{200^2}\)
\(=\frac{560000}{40000}\)
\(=14\)
tính nhanh
a) 1272 + 146 . 127 + 732
b) 1002 - 982 + 982 -972+ 962 - 952 ..........+ 22 - 12
c) 342 + 662 + 68.66
a/ \(127^2+146\cdot127+73^2=127^2+2\cdot73\cdot127+73^2=\left(127+73\right)^2=200^2=40000\)
b/ \(100^2-99^2+98^2-97^2+...+2^2-1^2=\left(100^2-99^2\right)+\left(98^2-97^2\right)+...+\left(2^2-1^2\right)\)
\(=100+99+98+97+...+2+1=\frac{\left(100\right)\left(100+1\right)}{2}=5050\)
c/ \(34^2+66^2+68\cdot66=34^2+66^2+2\cdot34\cdot66=\left(34+66\right)^2=100^2=10000\)
1. Tìm x:
a. 2x.(2x-1)^2 - 3x.(x+3).(x-3) - 4x.(x+1)^2 - x^3 = x^3 - 16.x^2 + 1
b. x.(x-2)^2 + 3x.(2x-1)^2 - 13.x^2 + 16.x^2 = 5x+2
2. Tính nhanh
a. 127^2 + 146 x 127 + 73^2
b. 9^8 x 2^8 - ( 18^4 - 1 ) x ( 18^4 + 1 )
help pls
Tính bằng cách thuận tiện nhất
a) 50 x 36 x 2
b) 127 + 1 + 73 + 39