The First Approach
The first approach to solving equations involves doing the same thing to each side of the equation or, if you like, using inverse operations.

     x – 3 = 5                     [Solve for x]
     x – 3 (+3) = 5 (+3)     [To get x alone, add 3 to each side of the equation]
     x = 5 +3                      [The 3s on the left cancel out]
     x = 8

The Second Approach
This approach involves moving items across the equal sign. Remember that you can move anything as long as you change its sign.

     x – 3 = 5                     [Solve for x]
     x – 3 = 5                     [To get x alone, -3 must move across the equal sign]
     x = 5 +3                      [–3 becomes +3 when it moves across the equal sign]
     x = 8

SAMPLE PRACTICE QUESTIONS FOR EQUATIONS WITH 1 OR 2 VARIABLES

1. If √x -14 = (- | 2³|), then what is the value of x?

     Solution
     √x - 14 = - | 8 | --> √x -14 = - 8 --> √x = 6 --> x = 36

2. If 2x + 2y = 14, then what is the value of 3x in terms of y?

     Solution
     A) “In terms of y” means that the final answer will include y: (x = ?y)
          2x+ 2y = 14 --> x + y = 7 --> x = 7 - y

     B) The value of x has been determined, but the final form is not x = ?y, but 3x = ?y
          x = 7 - y --> 3(x) = 3(7 - y) --> 3x = 21 - 3y

SAT Math: Equations with 1 or 2 Variables

Lesson Includes:

—Approaches to Math Equations

—Sample Practice Questions

—Practice Questions

Math

SAT Reading

SAT Writing

SAT Vocabulary

Equations Review Quiz

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