ACT · Elementary Algebra · Single-variable linear equations
Question act-q-00283
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The question
If 3x − 6 = 9, what is the value of x?
- 4
- 5
- -5
- 6
Show answer & worked solution
Answer: 5
Worked solution. Subtract -6 from both sides: 3x = 15. Divide both sides by 3: x = 5.
Why each wrong choice is wrong. The off-by-one and negated answers are common arithmetic-slip distractors. Watch the sign of the constant term when you move it across the equals sign.
Test-day tactic. When the stem is short, do the algebra straight rather than plugging in answer choices — it's faster.
About this question type
Items present a linear equation, possibly with parentheses or fractional coefficients, and ask for the value of the variable.
You will see a question shaped like this one on roughly every other official ACT form, typically at a moderate position in the section — solidly within the range that separates a 600-band student from a 700-band student. Treat any miss in this subtopic as a signal to drill the subtopic page before you do another full practice test.