Question

Difficulty: MediumSimplifying Expressions and Combining Like Terms

When the expression 4x(x2y)(2x3y)2+5y(2xy)4x(x - 2y) - (2x - 3y)^2 + 5y(2x - y) is simplified to the form Ax2+Bxy+Cy2Ax^2 + Bxy + Cy^2, where AA, BB, and CC are constants, what is the value of BB?

Answer: 14

Answer

The value of the coefficient BB is 14.
Expanding the entire expression yields 4x28xy4x2+12xy9y2+10xy5y24x^2 - 8xy - 4x^2 + 12xy - 9y^2 + 10xy - 5y^2. Grouping and combining the xyxy terms gives (8+12+10)xy=14xy(-8 + 12 + 10)xy = 14xy. Therefore, the coefficient BB is 14.

Step-by-Step Solution

1
Expand the first term
4x28xy4x^2 - 8xy
Distribute 4x4x to both terms inside the parentheses: 4x(x)4x(2y)=4x28xy4x(x) - 4x(2y) = 4x^2 - 8xy.
2
Expand the squared binomial and apply the negative sign
4x2+12xy9y2-4x^2 + 12xy - 9y^2
Use the binomial expansion formula (2x3y)2=4x212xy+9y2(2x - 3y)^2 = 4x^2 - 12xy + 9y^2, then multiply each term by 1-1.
3
Expand the third term
10xy5y210xy - 5y^2
Distribute 5y5y to both terms inside the parentheses: 5y(2x)5y(y)=10xy5y25y(2x) - 5y(y) = 10xy - 5y^2.
4
Combine the coefficients of the like terms
0x2+14xy14y20x^2 + 14xy - 14y^2
Sum the coefficients for each corresponding variable group: (44)x2+(8+12+10)xy+(95)y2(4 - 4)x^2 + (-8 + 12 + 10)xy + (-9 - 5)y^2.

Key Concept

Simplifying Algebraic Expressions and Combining Like Terms
Rate this question