Respuesta :

Nepalieducation

Answer:

6

Step-by-step explanation:

[tex]Here,\\\\\hookrightarrow x^{2} +y^{2} =20\:and\:xy=7\\\\Now,\\\\\hookrightarrow (x - y)^{2} \\\\Applying\:formula\\\\\hookrightarrow (x-y)^{2} =x^{2} -2xy+y^{2} \\\\Then\: we\: get\\\\\hookrightarrow x^{2} -2xy+y^{2} \\\\\hookrightarrow x^{2} +y^{2} -2xy\\\\\hookrightarrow 20-(2\times7)[Because\:x^{2} +y^{2} =20\:and\:xy=7]\\\\\hookrightarrow 20-14\\\\\hookrightarrow 6[/tex]

eunice1234

Answer: (x - y)² = 6

Concept:

Here, we need to know the concept of FOIL.

It is a way to expand squared or greater exponents parenthesis.

  • F irst
  • O uter
  • I nner
  • L ast

Step-by-step explanation:

Given information

x² + y² = 20

xy = 7

Given expression

(x - y)²

Expand parenthesis through FOIL

= (x - y) (x - y)

= x · x - x · y - x · y + y · y

= x² - 2xy + y²

Substitute values into the expression

= x² + y² - 2xy

= (20) - 2 (7)

= 20 - 14

= [tex]\boxed{6}[/tex]

Hope this helps!! :)

Please let me know if you have any questions

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