Question

Difficulty: EasySimplifying Expressions and Combining Like Terms

For all real values of aa and bb, what is the simplified form of the expression 3a3b2ab2(a3b5ab2)3a^3b - 2ab^2 - (a^3b - 5ab^2)?

  1. A
    2a3b7ab22a^3b - 7ab^2
  2. B
    4a3b+3ab24a^3b + 3ab^2
  3. C
    2a6b2+3a2b42a^6b^2 + 3a^2b^4
  4. 2a3b+3ab22a^3b + 3ab^2Answer
  5. E
    4a3b7ab24a^3b - 7ab^2

Answer

2a3b+3ab22a^3b + 3ab^2
The correct expression is found by distributing the negative sign across the parentheses to change the signs of the terms inside, yielding a3b+5ab2-a^3b + 5ab^2. Combining the like terms 3a3b3a^3b and a3b-a^3b gives 2a3b2a^3b, and combining 2ab2-2ab^2 and +5ab2+5ab^2 gives 3ab23ab^2.

Step-by-Step Solution

1
Distribute the negative sign to each term inside the parenthetical expression: (a3b5ab2)-(a^3b - 5ab^2).
a3b+5ab2-a^3b + 5ab^2
To remove the parentheses, we multiply each term inside by 1-1.
2
Rewrite the full expression with the parentheses removed: 3a3b2ab2a3b+5ab23a^3b - 2ab^2 - a^3b + 5ab^2.
3a3b2ab2a3b+5ab23a^3b - 2ab^2 - a^3b + 5ab^2
This sets up the expression for combining like terms.
3
Group and combine the like terms: (3a3ba3b)(3a^3b - a^3b) and (2ab2+5ab2)(-2ab^2 + 5ab^2).
2a3b+3ab22a^3b + 3ab^2
Only terms with the exact same variable parts and exponents can be combined by adding or subtracting their coefficients.

Key Concept

Simplifying algebraic expressions by distributing negative signs and combining like terms.
Estimated Time:45s
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