\(7846^{739}-7846^{738}=7846^{738}.\left(7846-1\right)=7846^{738}.7845⋮7845\)
\(7846^{739}-7846^{738}=7846^{738}.\left(7846-1\right)=7846^{738}.7845⋮7845\)
Cho \(\left|a-c\right|< 3,\left|b-c\right|< 2\) . Chứng minh rằng \(\left|a-b\right|< 5\)
Chứng minh rằng \(\left|x\right|+\left|y\right|=\left|x+y\right|\)
Chứng minh rằng:
\(\left|a+b\right|\le\left|a\right|+\left|b\right|\).
chứng minh rằng:\(\left|x-y\right|=\left|y-x\right|\)
Chứng minh rằng: \(\frac{3}{\left(1.2\right)^2}+\frac{5}{\left(2.3\right)^2}+\frac{7}{\left(3.4\right)^2}+.................+\frac{4031}{\left(2015.2016\right)^2}< 1\)
Chứng minh rằng :
\(\left(11+11+21+31+41+27+37+47\right)^{11}-\left(45+27+17\right)^{16}⋮2\)
Cho đa thức \(f\left(x\right)=a_4x^4+a_3x^3+a_2x^2+a_1x+a_0\)
Biết rằng: \(f\left(1\right)=f\left(-1\right);f\left(2\right)=f\left(-2\right)\)
Chứng minh: \(f\left(x\right)=f\left(-x\right)\forall x\)
1. Chứng minh rằng :
\(\left|2m-5\right|\le5\)
Cho \(\left(2x_1-3y_1\right)^{2004}+\left(2x_2+3y_2\right)^{2004}+\left(2x_3+3y_3\right)^{2004}+...+\left(2x_{2005}+3y_{2005}\right)^{2004}\le0\)
Chứng minh rằng: \(\dfrac{x_1+x_2+x_3+...+x_{2005}}{y_1+y_2+y_3+...+y_{2005}}=1,5\)