Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
2. Đặt c + d = x
Ta có: \(a+b+c+d=0\Rightarrow a+b+x=0\Rightarrow a^3+b^3+c^3+d^3=3abx\)
\(\Rightarrow a^3+b^3+c^3+d^3+3cd\left(c+d\right)=3ab\left(c+d\right)\)
\(\Rightarrow a^3+b^3+c^3+d^3=3ab\left(c+d\right)-3cd\left(c+d\right)=3\left(ab-cd\right)\left(c+d\right)\)
Câu 4:
\(a^{2016}+b^{2016}+c^{2016}=a^{1008}b^{1008}+b^{1008}c^{1008}+c^{1008}+a^{1008}\)
\(\Rightarrow2a^{2016}+2b^{2016}+2c^{2016}-2a^{1008}b^{1008}-2b^{1008}c^{1008}-2c^{1008}a^{1008}=0\)
\(\Rightarrow\left(a^{1008}-b^{1008}\right)^2+\left(b^{1008}-c^{1008}\right)^2+\left(c^{1008}-a^{1008}\right)^2=0\)
\(\Rightarrow a^{1008}=b^{1008},b^{1008}=c^{1008},c^{1008}=a^{1008}\)
\(\Rightarrow a=b,b=c,c=a\) (vì a,b,c > 0 nên \(a\ne-b,b\ne-c,c\ne-a\) )
\(\Rightarrow a-b=0,b-c=0,a-c=0\)
Thay vào A ta tính được A = 0
473 + 9.472 + 27.47 + 27
= 473 + 3.472.3 + 3.47.32 + 33
= ( 47 + 3 )3 ( HĐT số 4 )
= 503 = 125 000
1008³ - 3.1008².8 + 3.1008.8² - 2⁹
= 1008³ - 3.1008².8 + 3.1008.8² - 8³
= (1008 - 8)³
= 1000³
= 1000000000
\(1008^3-3\cdot1008^2+8+3\cdot1008\cdot8^2-2^6\)
\(=\left(1008-8\right)^3\)
=1000000000
a/ \(=47^3+3.47^2.3+3.47.3^2+3^3\)
\(=\left(47+3\right)^3=50^3=125000\)
b/ \(=102^3-3.102^2.2+3.102.2^2-2^3\)
\(=\left(102-2\right)^3=100^3=1000000\)
a: =>\(\dfrac{2x-4}{2014}+\dfrac{2x-2}{2016}< \dfrac{2x-1}{2017}+\dfrac{2x-3}{2015}\)
=>\(\dfrac{2x-2018}{2014}+\dfrac{2x-2018}{2016}< \dfrac{2x-2018}{2017}+\dfrac{2x-2018}{2015}\)
=>2x-2018<0
=>x<2019
b: \(\Leftrightarrow\left(\dfrac{3-x}{100}+\dfrac{4-x}{101}\right)>\dfrac{5-x}{102}+\dfrac{6-x}{103}\)
=>\(\dfrac{x-3}{100}+\dfrac{x-4}{101}-\dfrac{x-5}{102}-\dfrac{x-6}{103}< 0\)
=>\(x+97< 0\)
=>x<-97
a) ( 100 + 1 ) 3 = 100 3 + 3 . 100 2 + 3.100 + 1 = 1030301.
b) ( 47 + 3 ) 3 = 50 3 = 125000.
c) ( 300 – 1 ) 3 = 26730899.
d) ( 1008 – 23 ) 3 = 1000 3 = 10 9 .