Question

determine o valor numérico de:

A) a^2+b^2,sendo ab=10 e (a-b)^2=45


B)3xy,sendo(x-y)^2=18 e x^2 +y^2=96


C) (x-y)^2,sendo xy = 100 e x^2 + y^2 = 300


30 pontos heim!

Answer 1

A) a^2+b^2,sendo ab=10 e (a-b)^2=45

(a-b)^2= a² + b² - 2ab ==> 45 -2.(10) ==> 45 - 20 ==. 25
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B)3xy,sendo(x-y)^2=18 e x^2 +y^2=96

(x-y)^2= x² + y² - 2xy ==>  18 = 96 - 2xy ==> 2xy = 96-18

=> 2xy=78 ==> xy = 39 

3xy ==> 3.39 ==> 117
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C) (x-y)^2,sendo xy = 100 e x^2 + y^2 = 300

(x-y)^2= x² + y² - 2xy ==>  300 - 2(100) ==> 300 - 200 = 100