Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Algebra

Question:

The value of $27 a^3-2 \sqrt{2} b^3$ is equal to:

Options:

$(3 a-\sqrt{2} b)\left(9 a^2-2 b^2+6 \sqrt{2} a b\right)$

$(3 a-\sqrt{2} b)\left(9 a^2+2 b^2+6 \sqrt{2} a b\right)$

$(3 a-\sqrt{2} b)\left(9 a^2+2 b^2+3 \sqrt{2} a b\right)$

$(3 a-\sqrt{2} b)\left(9 a^2-2 b^2-3 \sqrt{2} a b\right)$

Correct Answer:

$(3 a-\sqrt{2} b)\left(9 a^2+2 b^2+3 \sqrt{2} a b\right)$

Explanation:

We know that,

a3 – b3 = (a – b) (a2 + b2 + ab)

= 27a3 - 2√2 b3

$(3 a-\sqrt{2} b)\left(9 a^2+2 b^2+3 \sqrt{2} a b\right)$