x − 2/3 = 5/6; what is x?

x − 2/3 = 5/6; what is x?

• A. 3/2
• B. 1
• C. 5/6
• D. 1/2

Answer: (A)

Isolating the variable by undoing what’s attached to it is the core idea. In this equation, x is decreased by 2/3 to give 5/6, so to undo that, add 2/3 to both sides. x = 5/6 + 2/3. Convert to a common denominator: 2/3 is 4/6, so this becomes x = 5/6 + 4/6 = 9/6, which simplifies to 3/2. So x equals 3/2. You can check by substituting: 3/2 minus 2/3 equals 9/6 minus 4/6 equals 5/6, which matches the right side.

Isolating the variable by undoing what’s attached to it is the core idea. In this equation, x is decreased by 2/3 to give 5/6, so to undo that, add 2/3 to both sides.

x = 5/6 + 2/3. Convert to a common denominator: 2/3 is 4/6, so this becomes x = 5/6 + 4/6 = 9/6, which simplifies to 3/2.

So x equals 3/2. You can check by substituting: 3/2 minus 2/3 equals 9/6 minus 4/6 equals 5/6, which matches the right side.