131 + 2006 =
Tính nhanh
a, 131×1961+1000/132×1961-961
b, A=2-4-6+8+10-12-14+16+…2002-2004-2006+2008
a. 131.1961+1000/131.1961+1961-961
=131.1961+1000/131.1961+1000=1
b(2-4-6+8)+(10-12-14+16)+...+(2002-2004-2006+2008)=0
tim chu so tan cung cua cac so sau
A=7^2006
B=9^1991
C=2^4+n+2(n thuoc tn
D=127^531
E=3^79+2014^1006
G=8^95.3^314
F=4^256-7^131
nhanh len nhe gap lam rui
Tính nhanh
(-131).(-25)+(-74).131-(-1).131
( -131 ) . ( -25 ) + ( -74 ) . 131 - ( -1 ) . 131
= 131 . 25 + ( -74 ) . 131 - ( -1 ) . 131
= 131 . [ ( 25 + ( -74 ) - ( -1 ) ]
= 131 . ( -50 )
= -6550
\(\left(-131\right)\left(-25\right)+\left(-74\right).131-\left(-1\right).131\)
\(=\left(-131\right)\left[\left(-25\right)+74-1\right]=\left(-131\right).48=-6288\)
(-215+131+57) - (131 - 215 + 47 )
( -215 + 131 + 57 ) - ( 131 - 215 +47 )
= -215 + 131 + 57 - 131 + 215 - 47
= ( -215 + 215 ) + ( 131 - 131 ) + ( 57 - 47 )
= 0 + 0 + 10
=10
mk giải xong rồi nhớ tick mk nha
(-215+131+57) - (131 - 215 + 47 )
=141- (-37)
=178
32006 +32006+32006+32006+32006+32006+32006 +32006+32006+32006=3x
Tính :
\(\frac{\frac{2006}{2}+\frac{2006}{3}+\frac{2006}{4}+...+\frac{2006}{2007}}{\frac{2006}{1}+\frac{2006}{2}+\frac{2006}{3}+...+\frac{1}{2006}}\)
A=2006^2005+1/2006^2006+1
B=2006^2006+1/2006^2007+1
so sánh A và B
A=2006^2005+1/2006^2006+1
B=2006^2006+1/2006^2007+1
Có : 2006A = 2006^2006+2006/2006^2006+1
= 1 + 2005/2006^2006+1 2006B
= 2006^2007+2006/2006^2007+1
= 1 + 2005/2006^2007+1
Vì : 2006^2006 < 2006^2007
=> 2006^2006+1 < 2006^2007+1
=> 2005/2006^2006+1 > 2005/2006^2007+1
=> 2016A > 2016B
=> A>B
A=2006^2005+1/2006^2006+1
B=2006^2006+1/2006^2007+1
so sánh A và B
Ta có:
\(A=\frac{2006^{2005}+1}{2006^{2006}+1}\)
\(\Rightarrow2006A=\frac{2006^{2006}+2006}{2006^{2006}+1}=\frac{\left(2006^{2006}+1\right)+2005}{2006^{2006}+1}=1+\frac{2005}{2006^{2006}+1}\)
Ta lại có:
\(B=\frac{2006^{2006}+1}{2006^{2007}+1}\)
\(\Rightarrow2006B=\frac{2006^{2007}+2006}{2006^{2007}+1}=\frac{\left(2006^{2007}+1\right)+2005}{2006^{2007}+1}=1+\frac{2005}{2006^{2007+1}}\)
Ta thấy:
\(\frac{2005}{2006^{2006}+1}>\frac{2005}{2006^{2007}+1}\Rightarrow2006A>2006B\Rightarrow A>B\)
Vậy A>B.
Ai k mình, mình k lại.
So sánh A và B :
a, A = 2006^2006 + 1 / 2006^2007 + 1 và B = 2006^2007 + 1 / 2006^2008 + 1
b, A = 2004 . 2005 - 1 / 2004 . 2005 và B = 2005 . 2006 - 1 / 2005 . 2006