When you plug h = 0 into the original expression, any term with an h drops out, and you end up with
or . Now plug h = 0 into each answer choice to see which ones equal .When you get to (C), it works, but you can’t stop there. It might just be a coincidence. When you pick
numbers, look at every answer choice. (E) also works for h = 0. At least you know one of those is the
correct answer, and you can decide between them by picking another value of h.
THE GOLDEN RULE OF EQUATIONS
You probably remember the basic procedure for solving algebraic equations: Do the same thing to
both sides. You can do almost anything you want to one side of an equation as long as you preserve
the equality by doing the same thing to the other side. Your aim in whatever you do to both sides is
to get the variable (or expression) you’re solving for all by itself on one side. Look at Example 5:
Example 5To solve this equation for j, do whatever is necessary to both sides of the equation to get j alone on
one side. Layer by layer, peel away all those extra symbols and numbers around the j. First, get rid of
that cube-root symbol. The way to undo a cube root is to cube both sides:
1. If , what is the value of j?