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2.5 Literal Equations and Formulas. I 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.
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2.5 Literal Equations and Formulas I 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 ONLY P.112 #11-33