Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Algebra

Question:

$(4x^3y - 6x^2y^2 + 4xy^3 - y^4)$ can be expressed as:

Options:

$(x - y)^4 - x^4$

$(x + y)^4 - y^4$

$x^4 - (x - y)^4$

$(x + y)^4 - x^4$

Correct Answer:

$x^4 - (x - y)^4$

Explanation:

(4x3y - 6x2y2 + 4xy3 - y4)

= 2xy3 - 2x2y2 - y4 + 4x3y + 2xy3 - 4x2y2

= -y(-2xy + 2x2 + y2) + 2xy (2x2 + y2 - 2xy)

= (2xy - y2) (2x2 + y2 - 2xy)

= (x2 - x2 - y2 + 2xy) (x2 + x2 + y2 - 2xy)

= [x2 - (x - y)2] [x2 + (x - y)2]

= x4 - (x - y)4