WAEC 2013 Mathematics · Question 1
If 9(2 - x) = 3, find x
Options
- A.1
- B.
- C.2
- D.
Answer: B.
Explanation written with AI and checked against the answer key
The question as written is ambiguous: "9(2 - x) = 3" could mean multiplication or an exponent. I'll work both ways and see which matches the options. Interpretation 1: multiplication, 9 × (2 − x) = 3 18 − 9x = 3 9x = 15 x = 15/9 = 5/3 5/3 is not among the options, so this is probably not what was intended. Interpretation 2: exponent, 9^(2−x) = 3 This is the original WASSCE question, and the formatting lost the superscript. Step 1: Write 9 as a power of 3: 9 = 3². Step 2: Substitute: (3²)^(2−x) = 3¹ Step 3: Multiply the exponents: 3^(2(2−x)) = 3¹ Step 4: The bases are equal, so equate the exponents: 2(2 − x) = 1 4 − 2x = 1 2x = 3 x = 3/2 Check: 9^(2 − 3/2) = 9^(1/2) = √9 = 3 ✓ Tip: When you see an equation with unknown exponents, rewrite every number with the same base (here, 3). Then equate the powers. Also remember that 9^(1/2) means the square root of 9.AI can make mistakes. Report anything that looks wrong.
Past questions © the examination body (JAMB/WAEC/NECO). DeeepSolve is not affiliated with them. Rights holders: see /copyright.