7.7 Transforming Formulas
• Goal: To solve for a given variable in a
formula
Why would you want to solve for
a formula?
• Solving for a variable in your formula can
give you more specific information
How to Solve Formulas…
• Our goal is to undo everything that is being
done to the variable that we are trying to
solve for by doing the opposite operation.
Steps
1. Clear Fractions by multiplying by LCD to
every term
2. Distribute
3. Collect like terms on same side of =
4. Undo addition and subtraction
5. Undo multiplication
Example 1: Solve for r
d=
t
r•t
d
r
t
t
Example 2: Solve for h
2•
r h
A
2
•2
2A  r  h
r
r
2A
h
r
Example 3:Solve for “c”.
abc
k
3
3k = a + b + c
-a-b -a-b
3k – a - b = c
Example 4: Solve for “r”:
C=2r
C
r
2
Example 5: Solve for “m”:
E=m
2
c
E
m 2
c
Example 6:
Ex 7:
8B  5  A  8
8B  5 A  40
8B  40  5 A
Example 8:
Solve for l:
P=2l +2w
Example 9:
Solve for t:
v = 3k
t
Ex 10: x-a=a(y-b) solve for a
Assignment:
Worksheet