1. To Start – 10 Points!! Simplify the following:
4a + 3(3a - b) – 5b Use the distributive property! 4a + 9a - 3b – 5b Combine like terms! 13a - 8b
5x + 3(4 + x) Use the distributive property! 5x x Combine like terms! 8x + 12

2. Chapter 2: Solving one-step equations and inequalities
Section 2-4: Variables and Equations

3. Equations!!!
An Equation is a mathematical sentence with an equal sign = 11 x + 7 = 37 a + (-3) = 2a + 5 An Open Sentence is an equation with one or more variables.
A numerical expression = to a numerical expression.
A variable expression = to a numerical expression.
A variable expression = to a variable expression.

4. Practice!!
Is each equation true, false, or an open sentence??
= 18 6 = y = (-3) + 5y
True, because 18=18 False, because 6 ≠ 7 Open sentence, because there is a variable

5. You Try!! 9 - 7 = 3 8 + x = 2 4(5)=20 True, because 20=20
Is each equation true, false, or an open sentence??
9 - 7 = x = 2 4(5)=20
False, because 2≠3
Open sentence, because there is a variable.
True, because 20=20

6. Writing Equations!! 9 (-5) = 45 * False, because -45≠45!!!
Write an equation for nine times the opposite of five is forty-five. Is the equation true, false, or an open sentence? Nine times opposite of 5 is forty-five 9(-5)=45? 9
(-5) = 45 *
False, because -45≠45!!!

7. You Try!! 20 - x = 3 Open sentence because it has a variable!!!
Write an equation for Twenty minus x is three. Is the equation true, false, or an open sentence? Twenty minus x is three 20 – x = 3? 20 - x = 3
Open sentence because it has a variable!!!

8. You Try Again!! 4 (-5) = -20 * True, because -20=-20!!!
Write an equation for Four times the opposite of five is negative twenty. Is the equation true, false, or an open sentence? Four times opposite of 5 is negative twenty 4(-5)=-20? 4
(-5) =
-20 *
True, because -20=-20!!!

9. Solutions!!!!
A Solution is a value for a variable that makes an equation true. Ex. Is 30 a solution of the equation 170+x=200? Substitute 30 in for x =200? Yes, 30 is a solution of the equation

10. You Try!!!! Is the given number a solution of the equation?
8 + t = 2t; 1 Substitute 1 in for t! = 2(1) 9 = 2? No, 1 is not a solution!!!
9 – m = 3; 6 Substitute 6 in for m! 9 – 6 = 3 3 = 3? Yes, 6 is a solution to the equation!!

11. Homework!!!!
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1-6, 9-16, 20-27, 29-32