Solución

a=1,2,3,b=0,2,5,c=8,9,2;a(b×c)=9\bold{a}=\lang 1,2,3\rang, \bold{b}= \lang 0,2,5\rang, \bold{c}=\lang 8,9,2\rang; \bold{a}\cdot(\bold{b}\times\bold{c})=−9