ass="bmw">See 14.4: 7-12 for more
      practice.</span><span class="larsonfive">See Larson
      13.5:7&ndash;10 for more practice (remember to use matrix
      multiplication, not the formulas from the book).</span>
    </div>
      Suppose $f(x,y,z) = x+2y+3z^2$ and $x=u+v$, $y=2u-3v$,
    and $z=uv$. Our goal is to find how much $f$ changes if we were
    to change $u$ (so $\partial f/\partial u$) or if we were to
    change $v$ (so $\partial f/\partial v$). Try doing this problem
    without looking at