Factorise fully 6x² + 9x.
Answer and explanation
Correct answer: B. 3x(2x + 3)
- Step 1: The highest common factor of 6x² and 9x is 3x. Step 2. 6x² ÷ 3x = 2x and 9x ÷ 3x = 3. Step 3. So 6x² + 9x = 3x(2x + 3). Answer: 3x(2x + 3). Why not the others: 3(2x² + 3x): This takes out only the 3, leaving a common factor of x. x(6x + 9): This takes out only the x, leaving a common factor of 3. 3x(2x + 9): This expands to 6x² + 27x, so the second term is wrong.
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