2.5 Literal Equations and FormulasI can rewrite and use literal equations and formulas

Literal Equations

• Involves two or more variables• You can use methods learned previously to

isolate any particular variable.• Ex: 11x + 3y = 67

Writing a Literal Equation

• You are ordering pizzas and sandwiches. You have a budget of $80.•Write an equation and define your variables.• Let x be the number of pizzas and y be the number of sandwiches.• 10x + 5y = 80

Solving for one of the Variables

• How many sandwiches can you buy if you buy 3 pizzas?• So x = 3 and we must solve for y.• 10x + 5y = 80• 5y = 80 – 10x• y = 16 – 2x• y = 16 – 2(3)• y = 16 – 6 = 10 sandwiches

Rewriting a literal equation

•What equation do you get when you solve ax – bx = c for x?• Factor out the x • x(a – b) = c• Divide by a – b • x = • It is ok to divide by a variable or variable

expression.

Formulas• An equation that states a relationship between

quantities.• They are special types of literal equations.• Some use the same variables, but they are

defined differently.• It is so important to DEFINE YOUR VARIABLES!

• Ex:

You try!

•What is the radius of a circle with a circumference of 64 ft? Round to the tenth.• Formula for circumference:• Solve for r:

• Substitute 64 for C:• Use 3.14 for pi:

Assignment

ODDS ONLYP.112 #11-33