618 Worked-Out Solutions to Exercises: Chapters 1 to 9
The first addend in this expression is ready to go! We can use the distributive laws on the
second and third terms to get
ux+uy+uz+vx+wx+ (v+w)(y+z)
The final term can be multiplied out using the product of sums rule from the chapter
text. This gives us
ux+uy+uz+vx+wx+vy+vz+wy+wz
We can use the commutative law of addition, in its generalized form, to rearrange these
terms so the whole sum is easier to remember:
ux+uy+uz+vx+vy+vz+wx+wy+wz