ACT · Pre-Algebra · Fractions, decimals, and integers
Question act-q-00230
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The question
If 8x − 9 = 7, what is the value of x?
- 2
- 3
- -2
- 1
Show answer & worked solution
Answer: 2
Worked solution. Subtract -9 from both sides: 8x = 16. Divide both sides by 8: x = 2.
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 test addition, subtraction, multiplication, and division of fractions and decimals; conversion between fractions, decimals, and percentages; and order of operations on mixed expressions.
You will see a question shaped like this one on roughly every other official ACT form, typically at the back end of the section, where the score gradient is steepest. Treat any miss in this subtopic as a signal to drill the subtopic page before you do another full practice test.