Question

If X + Y equal to 5 and x y equal to 6 find the value of x cube + y cube how​

Answer 1

x³ + y³ = 35

Explanation:

Using the following identities

(x + y)² = x² + 2xy + y² , then

5² = x² + y² + 2(6)

25 = x² + y² + 12 ( subtract 12 from both sides )

13 = x² + y² → (1)

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x³ + y³ ← is a sum of cubes and factors as

x³ + y³ = (x + y)(x² - xy + y² )

= 5(x² + y² - 6) ← substitute (1)

= 5(13 - 6) = 5 × 7 = 35

Answer 2

35

Explanation:

if X+Y=5&XY=6 we can guess the numbers easly the numbers are 2&3.

so X^3+Y^3=(2)^3+(3)^3

=2*2*2+3*3*3

=8+27

=35

i hope it helps you