2. Solving One-Step Equations Jennifer Barrall 9 th Grade Algebra Click to Continue

3. First, click on an image or link to learn about equations. Next, click on an image or link to learn how to solve one-step equations. Review Question

4. What is an Equation? Equation: A mathematical statement that says two things are equal An equation is made up of two expressions, one on each side of the equal sign One-step equations contain one variable: a symbol for an unknown number (“x”, “y”, etc.) – Numbers that we know are called Constants The variable is n. The constants are 7 and 10. Return to Main Menu

5. Balancing Equations Equations must be balanced When solving equations, the numbers on one side of the equal sign must be equal to the numbers on the other side of the equal sign The goal of solving equations is to get the variable (x) on one side of the equal sign 3 must be moved to the other side of the equal sign to get the variable, x, by itself. Return to Main Menu

6. Isolating “X” The variable must be isolated on one side of the equal sign to solve the one-step equation First, identify what must be moved to get “x” by itself Then, look for what operation is being used The operation being used is subtraction. 9 must be moved to get x by itself Return to Main Menu

7. Solving One-Step Equations To get “x” alone the opposite operation must be used on the constant What you do on one side of the equal sign you must do to the opposite side If the operation is addition, then use subtraction and vice versa If the operation is multiplication, then use division and vice versa In the first equation, 4 must be added to both sides to solve for x. In the second equation, 3 must be divided by x to both sides to solve for x. Return to Main Menu

8. Solving Addition Equations In this example, the variable is “y” and the constant being added to “y” is 14. What does “y” equal? Check your answer: Replace “y” with 6 in the equation. 6 + 14 = 20 20 = 20 The equation is balanced, therefore “y” equals 6. + 14 – 14 = 0 By subtracting 14 to both sides, the 14 on the left side of equal sign cancels out. The equation would look like this: y + 0 = 6 Return to Main Menu

9. Solving Subtraction Equations In this example, “x” is the variable and the constant being subtracted from “x” is 120. What does “x” equal? -120 + 120 = 0 By adding 120 to both sides, the 120 on the left side of the equal sign cancels out. The equation would look like this: X + 0 = 200 Check your answer: Replace “x” with 200 in the equation. 200 – 120 = 80 80 = 80 The equation is balanced, therefore “x” equals 200. Return to Main Menu

10. Solving Multiplication Equations In this example, the variable is “n” and the constant being multiplied by “n” is 3. What does “n” equal? Check your answer: Replace “n” with 4 in the equation. 3 × 4 = 12 12 = 12 The equation is balanced, therefore “n” equals 4. Return to Main Menu

11. Solving Division Equations In this example, the variable is “k” and the constant being divided by “k” is 2. What does “k” equal? Check your answer: Replace “k” with 32 in the equation. 32 ÷ 2 = 16 16 = 16 The equation is balanced, therefore “k” equals 32. Return to Main Menu

12. Review Question Solve the equation for “x” 4 + x = 15 A.X = 11X = 11 B.X = 12X = 12 C.X = 19X = 19

13. That is Correct!! Good job! By subtracting 4 from both sides of the equal sign you have found the solution for x. 4 + x = 15 -4 x = 11 Click to Continue

14. “x” does not equal 12. Check your work. You may have made a calculation error. Go back and try again. Back to Question

15. “x” does not equal 19. Check your work. Make sure you used the correct operation to isolate “x.” Go back and try again. Back to Question

16. C ONGRATULATIONS !!! Y OU HAVE COMPLETED THIS LESSON ON SOLVING ONE - STEP EQUATIONS. Click on the image below to return to the title slide for the next student: