Cho \(\left(x-4\right).f\left(x\right)=\left(x-5\right).f\left(x+2\right)\). Chứng tỏ rằng f(x) có ít nhất 2 nghiệm
Bài 1: Tìm x biết: \(\left|x-3\right|+\left|x+2\right|=7\)
Bài 2: CMR: \(\frac{1}{4}+\frac{1}{4^2}+\frac{1}{4^3}+...+\frac{1}{4^{999}}+\frac{1}{4^{1000}}< \frac{1}{3}\)
Bài 3: Tìm x biết:
a) \(x\left(x-2\right)\left(x-3\right)>0\)
b) \(x\left(x-2\right)\left(x-3\right)< 0\)
Tìm \(x,\) biết:
a) \(4\left|3x-1\right|+\left|x\right|-2\left|x-5\right|+7\left|x-3\right|=12\)
b) \(3\left|x+4\right|-\left|2x+1\right|-5\left|x+3\right|+\left|x+9\right|=5\)
c) \( \left|2\frac{1}{5}-x\right|+\left|x-\frac{1}{5}\right|+8\frac{1}{5}=1,2\)
d) \(2\left|x+3\frac{1}{2}\right|+\left|x\right|-3\frac{1}{2}=\left|2\frac{1}{5}-x\right|\)
tìm x biết :
\(\left|x-1\right|+2.\left|x-2\right|+3.\left|x-3\right|+4.\left|x-4\right|+5.\left|x-5\right|+20x=0\)
Tìm x:
\(3\left|x+4\right|-\left|2x+1\right|-5\left|x+3\right|+\left|x-9=5\right|\)
\(\left|x-2\right|+\left|x-3\right|+\left|2x-8\right|=9\\ \left|x+2\right|+\left|x+3\right|+\left|x+1\right|=4\\ \left|x+\dfrac{1}{1.5}\right|+\left|x+\dfrac{1}{5.9}\right|+\left|x+\dfrac{1}{9.13}\right|+...+\left|x+\dfrac{1}{397.401}\right|=101x\)
Tìm x biết rằng :
a) \(\left|x-4\right|+\left|x+2\right|=3\)
b) \(\left|x-2\right|+\left|x-3\right|=6\)
c)\(\left|x+2\right|-\left|3+x\right|=7\)
tìm các sos tự nhiên x,y biết rằng
\(\left(2^x+1\right).\left(2^x+2\right).\left(2^x+3\right).\left(2^x+4\right)\)-5^y=359
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: \(f\left(x\right)=f\left(-x\right)\forall x\)
Tìm x biết: \(\frac{4}{\left(x+2\right).\left(x+6\right)}+\frac{7}{\left(x+6\right).\left(x+13\right)}=\frac{2x+1}{\left(x+2\right).\left(x+16\right)}-\frac{3}{\left(x+13\right).\left(x+16\right)}\)