1. 3.6 Literal Equations and Formulas
Literal “letter” equations: an equation that uses more than one letter as a variable.
D=rt
A=bh
C= d
I=prt
You can solve the equation for any of the variables.

2. Practice
For D=rt solve for r
D = rt t t
D = r t

3. Practice For P=2b + 2h, solve for h P = 2b + 2h -2b -2b P - 2b = 2h

4. Practice For I = prt solve for p (Interest = principle ∙ rate ∙ time)
I = prt rt rt
I = p rt

5. Try these
I = prt pr pr
I = t pr
50____ = t 350 (.10)
50 = t 35
~1.43 years = t
How long will it take me to make $50 interest on $350 at 10% interest?
Remember to use I=prt

6. Try these x = 4y – 16 6 Solve for y 6x = 4y – 16 +16 +16 x = 4y – 16 6