4
	a)
=(a1e1+a2e2+a3e3)x(b1e1+c1e1+b2e2+c2e2+b3e3+c3e3)
=(a2e2*e3(b3+c3)+a3e3*e2(b2+c2)+a3e3*e1(b1+c1)+a1e1*e3(b3+c3)+a1e1*e2(b2+c2)+a2e2*e1(b1+c1))
=a2(b3+c3)e1 - a3(b2+c2)e1 + a3(b1+c1)e2 +a1(b3+c3)e2 +a1(b2+c2)e3 + a2(b1+c1)e3 
=a2b3e1-a3b2e1+a3b1e2-a1b3e2+a1b2e3-a2b1e3+
a2c3e1-a3c2e1+a3c1e2-a1c3e2+a1c2e3-a2c1e3+
=axb+axc
	b)
=(a1e1+a2e2+a3e3)*(b2c3e1-b3c2e1+b3c1e2-b1c3e2+b1c2e3-b2c13)
=a1(b2c3-b3c2) + a2(b3c1-b1c3) + a3(b1c2-b2c1)
=a1b2c3-a1b3c2 + a2b3c1-a2b1c3 + a3b1c2-a3b2c1
=c1(a2b3-a3b2)+c2(a3b1-a1b3)+c3(a1b2-a2b1)
=c*(axb)
=b1(a3c2-a2c3)+b2(a1c3-a3c1)+b3(a2c1-a1c2)
=b*(axc)
