Algebra

Quantitative Aptitude (Hr Patwari )

Title

45:30

Video Progress

8 of 24 completed

Notes Progress

5 of 15 completed

MCQs Progress

38 of 100 completed

Subjective Progress

8 of 20 completed

Continue to Next Topic

Indian Economy - Understanding the basics of Indian economic system

Next Topic

Download Solution PDF

If x³ + y³ = 9 and x + y = 3, then the value of x⁴+ y⁴is,

Explanation:

x³+y³ = (x + y) × (x² − xy + y²)
Putting given values of x³+y³ and (x + y)
9 = 3 × ((x+y)² − 3xy)
= 3 × (9 − 3xy)
= 27 − 9x
9xy = 18
xy = 2
x⁴ + y⁴ = (x² + y²)² - 2x²y²
= (x2 + y2)² - 2*4 [Putting value of xy]
= ((x + y)² - 2xy)²- 2*4 [Putting values of (x+y) and xy]

= (9 - 4)² - 2*4 = 17

Hence, option 3 is the correct answer.

By: Amit Kumar

Profile ResourcesReport error

Trial Period Ended