Question

What should be added to -3x²+7xy-y² to get 5xy+y²?
please give step-by-step explanation ​

Answer 1

Let 'p' be added to -3x^2 + 7xy -y^2 to get 5xy + y^2.

So, -3x^2 + 7xy - y^2 + p = 5xy + y^2.

p = 5xy + y^2 - { -3x^2 + 7xy - y^2 } .

{ Transposing} .

Opening the bracket :

p = 5xy + y^2 + 3x ^2 - 7xy + y^2 .

{ When we open the bracket , the signs change because of minus sign }.

p = - 2xy + 2y^2 + 3x^2

Rearranging this, we get :

p = 3x^2 - 2xy + 2y^2.

Hence , 3x^2 - 2xy + 2y^2 should be added to -3x^2 + 7xy -y^2 to get 5xy + y^ 2.

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