SAT Subject Test Mathematics Level 2

“IN TERMS OF”

So far in this chapter, solving an equation has meant finding a numerical value for the unknown.
When there’s more than one variable and only one equation, it’s impossible to get numerical
solutions. Instead, what you do is solve for the unknown in terms of the other variables.

To solve an equation for one variable in terms of another means to isolate the one variable on one
side of the equation, leaving an expression containing the other variable on the other side of the
equation.

For example, to solve the equation 3 x − 10y = −5x + 6y for x in terms of y, isolate x :

Now look at the next example, which asks you to solve “in terms of.”

Example 8

You want to get z on one side by itself. The first thing to do is to eliminate the denominator by
multiplying both sides by r^2 + z:

1. If    ,  what    is  the value   of  z   in  terms   of  p,  q,  and r?

(A)

(B)

(C)

(D)

(E)