1) Cho \(a^2+b^2+c^2+3=2\left(a+b+c\right)\)
CMR: \(a=b=c=1\)
2) CMR: nếu \(\left(a^2+b^2\right)\left(x^2+y^2\right)=\left(ax+by\right)^2\) thì \(\dfrac{a}{x}=\dfrac{b}{y}\)
3) Cho \(\left(a^2+b^2+c^2\right)\left(x^2+y^2+z^2\right)=\left(ax+by+cz\right)^2\)
CMR: \(\dfrac{a}{x}=\dfrac{b}{y}=\dfrac{c}{z}\)
Loga
Toán lớp 8
