Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Algebra

Question:

If $a^3-b^3=2349$ and $(a-b)=9$, then $(a+b)^2-a b$ is equal to:

Options:

280

244

261

229

Correct Answer:

261

Explanation:

If $a^3-b^3=2349$

$(a-b)=9$

$(a+b)^2-a b$ = (a2 + ab + b2) ( On solving)

(a3 – b3) = (a – b) (a2 + ab + b2)

= 2349 = 9 (a2 + ab + b2)

= (a2 + ab + b2) = 261