Choose the one alternative that best completes the statement or answers the question.
Solve.
-$A = P ( 1 + n r )$ for $r$
A) $r = \frac { P n } { A - P }$

B) $r = \frac { A - P } { P n }$

C) $r = \frac { P - A } { \operatorname { Pn } }$

D) $r = \frac { A } { n }$

Question

Choose the one alternative that best completes the statement or answers the question.
Solve.
-$A = P ( 1 + n r )$ for $r$
A) $r = \frac { P n } { A - P }$

B) $r = \frac { A - P } { P n }$

C) $r = \frac { P - A } { \operatorname { Pn } }$

D) $r = \frac { A } { n }$

Quizplus · Accepted Answer

We want to isolate the variable r, so we first undo the multiplication with P and n by dividing both sides by Pn:

$\frac { A } { Pn } = 1 + r$

Subtracting 1 from both sides, we get:

$\frac { A } { Pn } - 1 = r$

Combining the fractions on the left-hand side, we get:

$\frac { A - Pn } { Pn } = r$

Finally, we can flip the fraction to get rid of the division and obtain:

$r = \frac { A - P } { Pn }$

Choose the One Alternative That Best Completes the Statement or Answers