Question

Difficulty: HardSimplifying Expressions and Combining Like Terms

Match each algebraic expression on the left with its fully simplified equivalent expression on the right for all real values of mm and nn.

  • m(m23mn)2n(m2n2)(m3mn2)m(m^2 - 3mn) - 2n(m^2 - n^2) - (m^3 - mn^2)5m2n+mn2+2n3-5m^2n + mn^2 + 2n^3
  • (mn)3m(m23n2)+n3(m - n)^3 - m(m^2 - 3n^2) + n^33m2n+6mn2-3m^2n + 6mn^2
  • 3mn(mn)2m(n2mn)(m2n5mn2)3mn(m - n) - 2m(n^2 - mn) - (m^2n - 5mn^2)4m2n4m^2n
  • m2(2mn)n(m2n2)(m3+n3)m^2(2m - n) - n(m^2 - n^2) - (m^3 + n^3)m32m2nm^3 - 2m^2n

Answer

The correct matches are: (1) m(m23mn)2n(m2n2)(m3mn2)m(m^2 - 3mn) - 2n(m^2 - n^2) - (m^3 - mn^2) matches with 5m2n+mn2+2n3-5m^2n + mn^2 + 2n^3; (2) (mn)3m(m23n2)+n3(m - n)^3 - m(m^2 - 3n^2) + n^3 matches with 3m2n+6mn2-3m^2n + 6mn^2; (3) 3mn(mn)2m(n2mn)(m2n5mn2)3mn(m - n) - 2m(n^2 - mn) - (m^2n - 5mn^2) matches with 4m2n4m^2n; and (4) m2(2mn)n(m2n2)(m3+n3)m^2(2m - n) - n(m^2 - n^2) - (m^3 + n^3) matches with m32m2nm^3 - 2m^2n.
Each expression is simplified by systematically expanding parenthetical groups and collecting like terms with identical variable powers.

Step-by-Step Solution

1
Simplify the expression m(m23mn)2n(m2n2)(m3mn2)m(m^2 - 3mn) - 2n(m^2 - n^2) - (m^3 - mn^2)
5m2n+mn2+2n3-5m^2n + mn^2 + 2n^3
Distribute each term across the parenthetical expressions: m33m2n2m2n+2n3m3+mn2m^3 - 3m^2n - 2m^2n + 2n^3 - m^3 + mn^2. Group the like terms: (m3m3)+(3m2n2m2n)+mn2+2n3(m^3 - m^3) + (-3m^2n - 2m^2n) + mn^2 + 2n^3, which simplifies to 5m2n+mn2+2n3-5m^2n + mn^2 + 2n^3.
2
Simplify the expression (mn)3m(m23n2)+n3(m - n)^3 - m(m^2 - 3n^2) + n^3
3m2n+6mn2-3m^2n + 6mn^2
Use the binomial expansion formula to expand (mn)3=m33m2n+3mn2n3(m - n)^3 = m^3 - 3m^2n + 3mn^2 - n^3. Distribute the m-m term to obtain m3+3mn2-m^3 + 3mn^2. Sum all the expressions and combine like terms: (m3m3)3m2n+(3mn2+3mn2)+(n3+n3)=3m2n+6mn2(m^3 - m^3) - 3m^2n + (3mn^2 + 3mn^2) + (-n^3 + n^3) = -3m^2n + 6mn^2.
3
Simplify the expression 3mn(mn)2m(n2mn)(m2n5mn2)3mn(m - n) - 2m(n^2 - mn) - (m^2n - 5mn^2)
4m2n4m^2n
Expand the terms by distributing the outer coefficients to get 3m2n3mn22mn2+2m2nm2n+5mn23m^2n - 3mn^2 - 2mn^2 + 2m^2n - m^2n + 5mn^2. Grouping similar variables yields (3+21)m2n+(32+5)mn2=4m2n+0=4m2n(3 + 2 - 1)m^2n + (-3 - 2 + 5)mn^2 = 4m^2n + 0 = 4m^2n.
4
Simplify the expression m2(2mn)n(m2n2)(m3+n3)m^2(2m - n) - n(m^2 - n^2) - (m^3 + n^3)
m32m2nm^3 - 2m^2n
Expand the terms by distributing the multiplication: 2m3m2nm2n+n3m3n32m^3 - m^2n - m^2n + n^3 - m^3 - n^3. Grouping like terms yields (2m3m3)+(m2nm2n)+(n3n3)=m32m2n(2m^3 - m^3) + (-m^2n - m^2n) + (n^3 - n^3) = m^3 - 2m^2n.

Key Concept

Simplifying multivariable expressions by distributing terms (including negative signs) and combining like terms.
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