They want me to find the 3 members of a decreasing geometric progression. And I am given that let them be $a,b,c$ $a+b+c=14$ and that $a^2+b^2+c^2=84$
I tried to express everything with the first so $a+a.q+a.q^2=14$
$a^2(1+q^2+q^4)=84$ (I tried to solve these to equations but couldn't. I can clearly see that the members are probably $8,4,2$ and $q=0,5$ but I can't show it.