Question

if x+y=5,x2+y2=111,then find the value of x3+y3​

Answer 1

Answer:

Step-by-step explanation:

Hope it May helps u....

Answer 2

Answer:

770

Step-by-step explanation:

Given :

x + y = 5 ....( i )

and

$\large x^2+y^2=111$

Squaring on both side to ( i )

$\large (x+y)^2=(5)^2\\\\\\\large \text{using identity (a+b)^2=a^2+b^2+2ab }\\\\\\\large x^2+y^2+2xy=25\\\\\\\large \text{putting value of x^2+y^2=111 }\\\\\\\large 111+2xy=25\\\\\\\large 111-25=-2xy\\\\\\\large -xy=\dfrac{86}{2}=43$

We have to find $x^3+y^3$

$\large \text{using identity (a)^3+(b)^3=(a+b)(a^2+b^2-ab) }\\\\\\\large (x)^3+(y)^3=(5)(111+43)\\\\\\\large (x)^3+(y)^3=(5)\times154\\\\\\\large (x)^3+(y)^3=770$

Thus we get answer 770.