Question

if x+y=5 and xy=6 ,find the value of x^3+y^3​

Answer 1

Hey mate,

We will express x in terms of y,

x = 6/y... (1)

Put (1)

In first equation,

6/y + y = 5

6+y^2 = 5y

Now we will rearrange terms and solve the upcoming quadratic equation,

y^2 - 5y +6 = 0

y^2 - 2y - 3 y +6 = 0

y(y-2) - 3(y-2) = 0

So y = 2, 3

Then x from(1)

= 3,2

Then required answers,

= 3^3 + 2^3

= 27 + 8

= 35

Note :- the answer will come same in both the cases.

So your answer is 35

Hope this helps you out!

Answer 2

the answer is.....x^3+y^3=35