JavaScript Adding and Multiplying
<p>Without changing this function:</p>

<pre><code>function operate(operator, operand1, operand2) {
    return operator(operand1, operand2);
}
</code></pre>

<p>I want to write out:</p>

<pre><code>var x = operator(add, operate(add, 2, 3), operate(multiply, 4, 5));
</code></pre>

<p>And get 25 as a value of x. How can I do this? </p>
