\(\frac{1,4.2012.6+4,2.4024+8,4.976}{1+2+3+4+...+999}\)

\(=\frac{8,4.2012+4,2.2.2012+8,4.976}{1+2+3+4+...+999}\)

\(=\frac{8,4\left(2012+2012+976\right)}{1+2+3+4+...+999}\)

\(=\frac{8,4.5000}{500.999}\)

\(=\frac{84.500}{999.500}\)

\(=\frac{84}{999}\)

\(=\frac{28}{333}\)

\(a,27.75+27.25\)

\(=27.\left(75+25\right)\)

\(=27.100\)

\(=2700\)

\(b,\left(-6\right)+20+\left(-4\right)\)

\(=\left(-6-4\right)+20\)

\(=-10+20\)

\(=10\)

\(c,2^2.3^1-\left(1^{2012}+2012^0\right):2\)

\(=4.3-\left(1+1\right):2\)

\(=12-2:2\)

\(=12-1\)

\(=11\)

a)27.75+27.25

=27.(75+25)

=27.100

=2700

b)(-6)+20+(-4)

=[(-6)+(-4)]+20

=(-10)+20

=10

c)2².3-(1²⁰¹²+2012⁰):2

=12-2:2

=12-1

=11

a)=27.(75+25)

 =27.100

 =2700

b)=(-6-4)+20

 =20-10

=10

c)=4.3-(1+1):2

 =12-2:2

=12-1

=11

\(\frac{1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{2012}}{\frac{2013}{1}+\frac{2014}{2}+\frac{2015}{3}+...+\frac{4024}{2012}-2012}\)

\(=\frac{1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{2012}}{\left(\frac{2013}{1}-1\right)+\left(\frac{2014}{2}-1\right)+\left(\frac{2015}{3}-1\right)+...+\left(\frac{4024}{2012}-1\right)}\)

\(=\frac{1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{2012}}{\frac{2012}{1}+\frac{2012}{2}+\frac{2012}{3}+...+\frac{2012}{2012}}\)

\(=\frac{1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{2012}}{2012.\left(1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{2012}\right)}\)

\(=\frac{1}{2012}\)

Ủng hộ mk nha ^_-

\(\Leftrightarrow\dfrac{2\cdot3\cdot...\cdot31}{\left(2\cdot3\cdot...\cdot31\right)\cdot\left(2\cdot2\cdot...\cdot2\right)\cdot2^6}=2^x\)

=>2^x=1/2^36

=>x=-36

ta co: 1/4=1/2(1+1) ;

2/6 = 1+1/2(2+1)..... 
=>ve trai =n/2(n+1).(n+1)/2(n+2).(n+2)/2(n+3)..... 
= (1/2)^36 
=> n= - 36

Phân số \(\frac{2013}{2011}\) phải là \(\frac{4023}{2011}\)