Algebra Demystified 2nd Ed

Chapter 7 linear equaTionS 205

The steps for solving for r in I = Prt are identical:

IPrt

IPtr

I

Pt

r

=

=

=

()

All of the formulas in the following examples and practice problems are
formulas used in business, science, and mathematics.

EXAMPLES

Solve for q in the formula P = pq − c (P and p are different variables).

Ppqc

cc

Pcpq

Pc

p

pq

p

Pc

p

q

=−

++

+=

+ =

+ =

Solve for C.

FC

FC

FC

FC

=+

−−

−=

−=⋅

−=

9

5

32

32 32

32 9

5

5

9

32 5

9

9

5

5

9

32

()

()

EXAMPLES

Solve for

EXAMPLES

Solve for