Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Algebra

Question:

If x4 + x2y2 + y4 = 525,

x2 + xy + y2 = 21, then

find x2 - xy + y2 .

Options:

22

25

27

30

Correct Answer:

25

Explanation:

Formula → x4 + y4 + x2y2 = (x+ y2 + xy) × (x+ y2 - xy)

⇒ 525 = 21 × (x+ y2 - xy)

⇒ x+ y2 - xy = \(\frac{525}{21}\) = 25