2. ALGEBRA LESSON 3 – SOLVING ONE-STEP ADDITION/SUBTRACTION EQUATIONS

3. ONE-STEP EQUATIONS An equation is a statement that says two expressions are equalAn equation is a statement that says two expressions are equal To solve an equation containing a variable means to find the value(s) of the variable that make(s) the equation true.To solve an equation containing a variable means to find the value(s) of the variable that make(s) the equation true. EXAMPLE: x = 4 is a solution to the equation x + 6 = 10 because we all know that 4 + 6 = 10 x = 11 is not a solution because 11 + 6 is not equal to 10 x = 11 is not a solution because 11 + 6 is not equal to 10

4. SOLVING ONE-STEP EQUATIONS A one-step equation is an equation that requires only one step to solve itA one-step equation is an equation that requires only one step to solve it

5. SOLVING EQUATIONS USING INVERSE OPERATIONS In order to solve any equation, we must use inverse operationsIn order to solve any equation, we must use inverse operations – the inverse of addition is subtraction – the inverse of subtraction is addition Essentially, you are trying to make it so the “x” is isolated. So, you are trying to make everything that is not attached to the “x” go away (turn into zero)

6. SOLVING EQUATIONS USING INVERSE OPERATIONS If you see addition in an equation, you will use subtraction to solve it.If you see addition in an equation, you will use subtraction to solve it. Same goes for subtraction, but you use addition.Same goes for subtraction, but you use addition. REMEMBER: WHAT IS DONE TO ONE SIDE OF AN EQUATION MUST ALSO BE DONE TO THE OTHER SIDEREMEMBER: WHAT IS DONE TO ONE SIDE OF AN EQUATION MUST ALSO BE DONE TO THE OTHER SIDE ALWAYS CHECK YOUR ANSWER TO MAKE SURE IT IS CORRECTALWAYS CHECK YOUR ANSWER TO MAKE SURE IT IS CORRECT

7. EXAMPLES OF ADDITION/SUBTRACTION EQUATIONS x + 8 = 10 The 8 is not attached to the x. How can I turn 8 into a zero? Show this! What you do to one side, you must do to the other. x + 8 = 10CHECK: - 8 -82 + 8 = 10? x = 210 = 10 yes

8. x – 9 = 11x – 9 = 11 Since the 9 is not attached to the x, make it go away. What would make 9 (in this case – 9) into zero? Show this on both sides.

9. MORE EXAMPLES

10. ANY QUESTIONS?????? HOMEWORK – Worksheet on Addition/Subtraction EquationsHOMEWORK – Worksheet on Addition/Subtraction Equations