Literal Equations and Formulas (2-5)

Vocabulary Literal Equation- An equation that involves two or more variables Formula- an equation that states a relationship among quantities

Rewriting a Literal Equation One pizza costs $10 One sandwich costs $5 You have $80 How many sandwiches can you buy if you get 3 pizzas? 6 pizzas? 1st: Define your variables: p = # of pizzas s = # of sandwiches

2nd : Write the equation 10p + 5s = 80 3rd: Ask yourself, What do I want to know? The # of sandwiches I can buy 4th: Isolate the variable that represents what you want to know 10p + 5s = 80 (Use inverse operations to get the s by itself)

10p + 5s = 80 5th: Subtract 10p from both sides of the equation -10p -10p 5s = 80 – 10p 6th: Now divide both sides by 5 5 5 s = 16 – 2p 7th: How can we determine the number of sandwiches if we buy 3 pizzas? -by substituting 3 in for p

s = 16 – 2p s = 16 – 2(3) s = 16 – 6 s = 10 sandwiches How many sandwiches can you buy with 6 pizzas? 4 sandwiches

Literal Equations with only Variables Solve V = bwh for height V = bwh bw bw V = h bw

Solve ax – bx = c for x Any ideas??? Use the Distributive Property!! x ( a – b) = c Now isolate x x ( a – b ) = c ( a – b ) (a – b) So x = 𝑐 (𝑎 −𝑏 )

You try: Go to textbook pg 110 Write each formula and solve for the following: Perimeter: solve for w Circumference: solve for r Area (rect): solve for l Area (triangle): solve for b Area (circle): solve for r Distance: solve for t Temperature: solve for F Area (trapezoid): solve for base 2