Question 20

If (x + y) = 3, xy = 2, then what is the value of $$x^3+y^3$$:

Solution

Given,

x + y = 3 and xy = 2

$$x^3+y^3\ =\ \left(x+y\right)\left(x^2+y^2-xy\right)$$

x + y = 3

squaring on both sides

$$\left(x+y\right)^2$$ = 9

$$x^2+y^2+2xy$$ = 9

$$x^2+y^2$$ = 9-4 = 5

$$x^3+y^3$$ = 3(5-2) = 9

Answer is option D.

Video Solution

video

View More Questions From Quadratic Equations

Create a FREE account and get:

All Quant Formulas and shortcuts PDF
40+ previous papers with detau solutions PDF
Top 500 MBA exam Solved Questions for Free

maruti sir image

MAT Quant Questions | MAT Quantitative Ability

MAT Linear Equations Questions MAT Logarithms Questions MAT Inequalities Questions MAT Quadratic Equations Questions MAT Number Series Questions MAT Arithmetic Questions MAT Mensuration Questions MAT Number Systems Questions MAT Averages, Ratio and Proportion Questions MAT Remainders Questions MAT Averages Mixtures Alligations Questions MAT Probability, Combinatorics Questions MAT Percentages Questions MAT Progressions and Series Questions MAT Data Sufficiency Questions MAT Time Speed Distance Questions MAT Profit and Loss Questions MAT Simple Interest Compound Interest Questions MAT Averages Questions MAT Time And Work Questions MAT Coordinate Geometry Questions MAT Profit And Loss Questions MAT Geometry Questions MAT Logarithms, Surds and Indices Questions MAT Venn Diagrams Questions MAT Functions, Graphs and Statistics Questions MAT Time, Speed and Distance Questions MAT Algebra Questions

MAT DILR Questions | LRDI Questions For MAT

MAT Special Charts Questions MAT Charts Questions MAT Puzzles Questions MAT Data Interpretation Basics Questions MAT 2D & 3D LR Questions MAT Routes And Networks Questions MAT Coins and Weights Questions MAT Maxima-Minima Questions MAT Data Interpretation Questions MAT Games and Tournamnents Questions MAT Table based DI Sets Questions MAT Venn Diagrams Questions MAT DI Miscellaneous Questions MAT Miscellaneous LR Questions MAT Quant Based LR Questions MAT Data change over a period Questions MAT DI with connected data sets Questions MAT Scheduling Questions MAT Truth Lie Concept Questions MAT Quant Based DI Questions MAT Arrangement Questions MAT Selection With Condition Questions

MAT Verbal Ability Questions | VARC Questions For MAT

MAT Odd One Out Questions MAT Miscellaneous Questions MAT Verbal Ability Questions MAT Grammar and Sentence Correction Questions MAT Critical Reasoning Questions MAT Para Summary Questions MAT Vocabulary Questions MAT Para Jumbles Questions MAT Reading Comprehension Questions