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Learn how to solve linear and literal equations, simplify equations, and solve for specific variables. Practice problems included.
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Algebra 2Warm-up: 8/23/2010 Simplify.
Answers • 4x-9 • 86-80x • 38-16x • 54x+14
Quiz Today operations with signed numbers NO CALCULATOR Main Events: Check: p. 14 #28-42 even, 50 **collect signed Honor Code Lesson Quiz PowerPoint Examples 1.3-1.4 Classwork: Practice Problems
Section 1.3-1.4 • Objective: Solve linear and literal equations for a specific variable. linear literal What’s the difference?
1.3 Solving Linear Equations x – 6 = 9 + 6 +6 x = 15 Example Solve for x: x – 6 = 9 To “undo” subtraction,use addition. Example Solve 112 = –14n 112 = –14n –14 –14 To “undo” multiplication,use division. –8 = n
Two step equation Example 7y – 2 = 19 undo addition (orsubtraction) first. +2 +2 7y = 21 undo multiplication (or division) last. 7y = 21 7 7 y = 3 Be sure to check your solution!
Sometimes, it is necessary to simplify the equation prior to solving it...Example 2x + 3(x – 5) = –10 Distribute first 2x + 3x – 15 = –10 5x – 15 = –10 + 15 +15 5x = 5 5x = 5 5 5 x = 1
Let’s look at an example that has variables on both sides of the equation...Ex. 5x + 6 = 2x – 3 The strategy to solve this type of problem is to get variables on one side, and numbers on the other side. variable side number side 5x + 6 = 2x – 3 – 6 – 6 5x = 2x – 9 –2x –2x 3x = – 9 x = – 3
1.4 Literal Equations and Formulas Literal Equation: Equation with more than one variable 3x + 2y = 6 This equation can be solved for either x or y.(We will be told which one to solve for). Literal Equation: Equation with more than one variable 3x + 2y = 6 This equation can be solved for either x or y. (We will be told which one to solve for). Here are other Literal Equations that you may have seen before: P = 2L + 2W Here are other Literal Equations that you may have seen before: Literal Equations and Formulas d=rt P = 2L + 2W You can solve for any of the variables in any of these equations.
The formula for the Perimeter of a Rectangle is P = 2L + 2W Example 1: Solve for W: P = 2L + 2W – 2L –2L P – 2L = 2W P – 2L = 2W2 2 P – 2L = W 2
Remember… Distributing vs. factoring Remember that you must distribute the -2 Now do this process in reverse (factor the GCF) What is the common factor? 10
Example 2: Solve for PA = P + Prt Since P is in two terms, we’re going to need to factor it out (think Greatest Common Factor) in order to isolate it. A = P(1 + rt) Now, isolate P by dividing both sides by(1 + rt) A = P(1 + rt)(1 + rt) (1 + rt) P = A 1 + rt
From Geometry, here’s the formula for theVolume of a cylinder: V = πr2h Example 3: Use the formula above to solve for h. h V = πr2h πr2 πr2 r h = V πr2
Here is the formula to find the area of an ellipse :A = πab b a a b Example 4: Find a if A = 65, b = 4 A = πab πb πb a = 65 a = A a ≈ 5.18 πb (3.14)(4)
Practice 1.4 1. Solve for y: 2. Solve for P: 3. Solve for l:
Homework:p. 22 # 35-60 (x5) p. 30 # 4-7(all) Closure: Think of a literal equation that would require factoring a GCF prior to solving