Số hsg:45.1/9=5hs

Số hs khá:5.3 2/3=... hs

Số hs tb: 45-5-(hs khá)=...hs

Đáp số:hsg:5hs

Hs khá:..hs

Hs tb: ...hs

Số hs giỏi : 45x1/9=5(hs)

số hs khá :5x11/3=18(hs)

số hs tb :45-(5+18)=22(hs)

a) 1³ + 2³ + 3³ + 4³ + 5³

= 1 + 8 + 27 + 64 + 125

= 9 + 27 + 64 + 125

= 36 + 64 + 125

= 100 + 125

= 225 

<=> 225 = 15²

b) 1³ + 2³ + 3³ + 4³ + 5³ + 6³

= 1 + 8 + 27 + 64 + 125 + 216

= 9 + 27 + 64 + 125 + 216

= 36 + 64 + 125 + 216

= 100 + 125 + 216

= 225 + 216

= 441

<=> 441 = 21²

a) 15²

b) 21²

\(2009A=\frac{2009^{2010}+2009}{2009^{2010}+1}=\)\(\frac{2009^{2010}+1+2008}{2009^{2010}+1}=1+\frac{2008}{2009^{2010}+1}\)

\(2009B=\frac{2009^{2009}+2009}{2009^{2009}+1}=\frac{2009^{2009}+1+2008}{2009^{2009}+1}\)\(=1+\frac{2008}{2009^{2009}+1}\)

Vì \(1+\frac{2008}{2009^{2010}+1}< 1+\frac{2008}{2009^{2009}+1}\) \(\Leftrightarrow A< B\)

\(A=\frac{2009^{2009}+1}{2009^{2010}+1}\Rightarrow2009A=\frac{2009^{2010}+2009}{2009^{2010}+1}\)

\(2009A=\frac{2009^{2010}+1}{2009^{2010}+1}+\frac{2008}{2009^{2010}+1}\)

\(2009A=1+\frac{2008}{2009^{2010}+1}\)

..... sory bn mk hơi luwoif chút nên bn tự lm tương tự vs phần B và so sánh nhé!^^

B={4;6;9;11}

B={4;6;9;11}

Đó là tháng 5,6,7

Quý 2 có tháng 5,6,7

Đặt :

\(A=\frac{2^{2014}+1}{2^{2014}}=\frac{2^{2014}}{2^{2014}}+\frac{1}{2^{2014}}=1+\frac{1}{2^{2014}}\)

\(B=\frac{2^{2014}+2}{2^{2014}+1}=\frac{2^{2014}+1+1}{2^{2014}+1}=\frac{2^{2014}+1}{2^{2014}+1}\)\(=1+\frac{1}{2^{2014}+1}\)

\(1+\frac{1}{2^{2014}}>1+\frac{1}{2^{2014}+2}\Leftrightarrow A>B\)