Question 178 of 480
Factorize completely 4abx - 2axy -12b2x + 6bxy
- A. 2x(a - 3b)(2b - y)
- B. 2x(3b - a)(2b - y)
- C. 2x(a - 3b)(y - 2b)
- D. 2x(2b - a)(3b - y)
Correct Answer:
A
Explanation
To factor the expression \( 4abx - 2axy - 12b^2x + 6bxy \) completely, we will follow a systematic approach. Let's break it down step-by-step.
### Step 1: Grouping Terms
First, we can group the terms in pairs to make factoring easier:
\[
(4abx - 2axy) + (-12b^2x + 6bxy)
\]
### Step 2: Factor Out Common Factors
Now, we will factor out the common factors from each group.
1. From the first group \( 4abx - 2axy \):
- The common factor is \( 2ax \).
- Factoring it out gives us:
\[
2ax(2b - y)
\]
2. From the second group \( -12b^2x + 6bxy \):
- The common factor is \( -6bx \).
- Factoring it out gives us:
\[
-6bx(2b - y)
\]
Now, we can rewrite the expression as:
\[
2ax(2b - y) - 6bx(2b - y)
\]
### Step 3: Factor Out the Common Binomial
Notice that both terms now have a common factor of \( (2b - y) \):
\[
(2b - y)(2ax - 6bx)
\]
### Step 4: Factor the Remaining Expression
Next, we need to factor the expression \( 2ax - 6bx \):
- The common factor here is \( 2x \):
\[
2x(a - 3b)
\]
### Step 5: Combine Everything
Putting it all together, we have:
\[
(2b - y)(2x(a - 3b))
\]
### Final Factorization
Thus, the complete factorization of the original expression is:
\[
2x(a - 3b)(2b - y)
\]
### Conclusion
The correct option is **A: \( 2x(a - 3b)(2b - y) \)**.
### Explanation of Other Options
- **Option B: \( 2x(3b - a)(2b - y) \)**: This is incorrect because the factor \( (3b - a) \) is not equivalent to \( (a - 3b) \). The signs are reversed, which changes the expression.
- **Option C: \( 2x(a - 3b)(y - 2b) \)**: This is incorrect because the factor \( (y - 2b) \) is not the same as \( (2b - y) \). The order of subtraction matters, and this would yield a different expression.
- **Option D: \( 2x(2b - a)(3b - y) \)**: This is incorrect because neither \( (2b - a) \) nor \( (3b - y) \) are factors of the original expression. The terms do not match the structure we derived.
### Revision Summary
- Factor by grouping terms to identify common factors.
- Always check for common binomials after initial factoring.
- Be cautious with the order of terms when factoring expressions.
- Verify your final factorization by expanding to ensure it matches the original expression.