Respuesta :

gmany

[tex](x-y)^2=x^2-2xy+y^2=(x^2+y^2)-2(xy)\\\\\text{We have}\ (x-y)^2=100\ \text{and}\ xy=20.\\\\\text{Substitute}\\\\100=(x^2+y^2)-2(20)\\100=(x^2+y^2)-40\qquad\text{add 40 to both sides}\\\\140=(x^2+y^2)\\\\Answer:\ \boxed{x^2+y^2=140}[/tex]

Answer: The value of [tex]x^2+y^2[/tex] is 140

Step-by-step explanation:

We are given an expression:

[tex](x-y)^2=100[/tex]

And,

xy = 20

Using the identity:

[tex](a-b)^2=a^2+b^2-2ab[/tex]

Solving the expression:

[tex]x^2+y^2-2xy=100[/tex]

Putting the value of 'xy' in above equation, we get:

[tex]x^2+y^2-2(20)=100\\\\x^2+y^2=100+40\\\\x^2+y^2=140[/tex]

Hence, the value of [tex]x^2+y^2[/tex] is 140