cho a,b khác 0 thỏa mãn a^2014 + b^2014 = a^2013 + b^2013 = a^2012 + b^2012
chứng minh rằng : a^2014 + b^2014 = a^2010 + b^2010
Cho A=2010+2011*2012;B=2012*2013-2014.Tính A/B
Cho A=2010+2011*2012;B=2012*2013-2014 .Tính A/B.
\(\frac{A}{B}=\frac{2010+2011.2012}{2012.2013-2014}=\frac{2010+2011}{2013-2014}=\frac{4021}{-1}=-4021\)
cho a,b dương và a^2010+b^2010=a^2011+b^2011=a^2012+b^2012 Tính S=a^2013+b^2014
Ta có:
\(a^{2010}+b^{2010}+a^{2012}+b^{2012}\)
\(=\left(a^{2010}+a^{2012}\right)+\left(b^{2010}+b^{2012}\right)\ge2a^{2011}+2b^{2011}\)
Dấu "=" xảy ra khi: \(\hept{\begin{cases}a^{2010}=a^{2012}\\b^{2010}=b^{2012}\end{cases}}\)
\(\Leftrightarrow\hept{\begin{cases}a=1\\b=1\end{cases}}\)
\(\Rightarrow a^{2013}+b^{2013}=2\)
Vậy \(S=2\)
Cho A = 2010+ 2011 x 2012 ; B = 2012 x 2013 – 2014
Tính A: B
\(\frac{A}{B}=\frac{2010+2011\times2012}{2012\times2013-2014}\)
B = 2012 x 2013 - 2014 = 2012 x (2011+2) - 2014 = 2012 x 2011 + 2012 x 2 - 2014 = 2012 x 2011 + 2010 = 2010 + 2011 x 2012
Thay B vào biểu thức tính thương, ta được:
\(\frac{A}{B}=1\)
Đáp số: 1
Nếu mình giúp đc bạn, thì cho mình nhé!
Cho A = 2010+ 2011 x 2012 ; B = 2012 x 2013 – 2014
Tính A: B
Bài giải
Ta có:
2010 + 2011 x 2012 /2012 x 2013 – 2014
= ( 2010 + 2011 x 2012) / (2012 x (2011 + 2) – 2014)
= ( 2010 + 2011 x 2012) / (2012 x 2011) + ((2012 x2 ) – 2014)
= ( 2010 + 2011 x 2012) / (2012 x 2011) + 2010
= 1/1
= 1
nhin vao de la bik = 1 rui ko can phai lam dai dong vay dau
Cho a > b > 0.Chứng minh rằng:\(\dfrac{a^{2014}-b^{2014}}{a^{2014}+b^{2014}}>\dfrac{a^{2013}-b^{2013}}{a^{2013}+b^{2013}}\)
Ch 2 số dương a , b thỏa mãn : a^2012 + b^2012 = a^2013 + b^2013 = a^2014 + b^2014 . Tính : P = 20a + 11b + 2013
Cho 2 số dương a, b thỏa mãn: a2012 + b2012 = a2013 + b2013 = a2014 + b2014.
Hãy tính M = 20a + 11b + 2013
ta có \(a^{2012}+b^{2012}=a^{2013}+b^{2013}\)
\(\Rightarrow a^{2012}-a^{2013}+b^{2012}_{ }-b^{2013}=0\)
\(\Rightarrow a^{2012}\left(1-a\right)+b^{2012}\left(1-b\right)=0\)\(\left(1\right)\)
tương tự \(a^{2013}+b^{2013}=a^{2014}+b^{2014}\)
\(\Leftrightarrow a^{2013}\left(1-a\right)+b^{2013}\left(1-b\right)=0\)\(\left(2\right)\)
trừ (1) cho (2)
ta có \(\left(a^{2012}-a^{2013}\right)\left(1-a\right)\)\(+\left(b^{2012}-b^{2013}\right)\left(1-b\right)=0\)
\(\Leftrightarrow a^{2012}\left(1-a\right)^2+b^{2012}\left(1-b\right)^2=0\)
mà\(a^{2012}\left(1-a\right)^2\ge0;b^{2012}\left(1-b\right)^2\ge0\)
\(\Rightarrow a=1;b=1\)
\(\Rightarrow M=20\times1+11\times1+2013=2044\)
lay cai dau tru cai thu 2
xong lay cai thu 2 tru cai thu 3
xong lay ket qua dau tim dc tru ket qua sau la tim dc a=b=1
roi thay vao tinh M la xong
Ta có: \(a^{2012}+b^{2012}=a^{2013}+b^{2012}=a^{2014}+b^{2014}\)
\(\Rightarrow a^{2012}+b^{2012}-2\left(a^{2013}+b^{2013}\right)+a^{2014}+b^{2014}=0\)
\(\Rightarrow a^{2012}+b^{2012}-2\left(a^{2013}+b^{2013}\right)+a^{2014}+b^{2014}=0\)
\(\Leftrightarrow\left(a^{1006}-a^{1007}\right)^2+\left(b^{1006}-b^{1007}\right)=0\)
Từ đó ta có 2 TH
\(\hept{\begin{cases}a^{1006}-a^{1007}=0\\b^{1006}-b^{1007}=0\end{cases}\hept{\begin{cases}a=0;a=1\\b=0;b=1\end{cases}}}\)
Vậy P=20.0+11.0+2013=2013
P=20.1+11.0+2013=2033
P=20.0+11.1+2013=2024
Tính A : B, biết :
A = 2010+2011 x 2012
B = 2012 x 2013 - 2014
\(A=4048142\)
\(B=4048142\)
\(4048142:4048142=1\)
2010+2011.2012=2010+4046132=4048142
2012.2013-2014=4050156-2014=4048142