1. 1.3 Solving Linear Equations p. 19

2. What is an equation? A statement in which 2 expressions are =A statement in which 2 expressions are = Ex: Which of the following are equations? a.3x-7=12b. 24x+5 c.2x-7x 2 +4x 3 d. 12x+3= -4x-8

3. Properties of Equality Addition prop of = - can add the same term to both sides of an equation.Addition prop of = - can add the same term to both sides of an equation. Subtraction prop of = - can subtract the same term from both sides of an equation.Subtraction prop of = - can subtract the same term from both sides of an equation. Multiplication prop of = - can multiply both sides of an equation by the same term.Multiplication prop of = - can multiply both sides of an equation by the same term. Division prop of = - can divide both sides of an equation by the same term.Division prop of = - can divide both sides of an equation by the same term. ** So basically, whatever you do to one side of an equation, you MUST do to the other!

4. To solve an equation for a variable: Do order of operations backwards (undo +/- first, then mult/div.)Do order of operations backwards (undo +/- first, then mult/div.) Keep going until the variable is by itself on one side of the equationKeep going until the variable is by itself on one side of the equation You may have to simplify each side first.You may have to simplify each side first.

5. Example: Solve for the variable.

6. Ex: Solve for x.

7. Ex: Solve the equations. 5(x-4)=5x+12 5x-20=5x+12 5x-20=5x+12 -20=12 -20=12 Doesn’t make sense! Answer: No solution 7x+14 -3x=4x+14 4x+14=4x+14 4x+14=4x+14 0=0 0=0 This one makes sense, but there’s no variable left! Answer: All real numbers

8. Dry ice is solid CO 2. It does not melt, but changes into a gas at -109.3 o F. What is this temperature in o C?

9. 1.4 Rewriting Equations & Formulas p. 26

10. Examples Solve 11x-9y= -4 for y.Solve 11x-9y= -4 for y. -11x -11x -11x -11x-9y=-11x-4 -9-9 -9 Solve 7x-3y=8 for x.Solve 7x-3y=8 for x. +3y +3y +3y +3y 7x=3y+8 7x=3y+8 7 7 7

11. Turn to page 28 in your book. Know the Common Formulas Chart on this page!

12. Ex: Solve the area of a trapezoid formula for b 1. A = ½ (b 1 +b 2 ) h A = ½ (b 1 +b 2 ) h 2A = (b 1 +b 2 ) h

13. Last Example: You are selling 2 types of hats: baseball hats & visors. Write an equation that represents total revenue.You are selling 2 types of hats: baseball hats & visors. Write an equation that represents total revenue. Total Revenue Price of baseball cap # of caps sold Price of visor # of visors sold R = p 1 B + p 2 V

14. Assignment