Question

7. a) 2a²b+3ab²-5a²b+6ab²+9a²b-4ab²=
b) (2x²+4xy) + (y²-2xy)-(x²+4y²-5xy) + ( x²-y²)=

Answer 1

$\\ a) \\ 2a^2b+3ab^2-5a^2b+6ab^2+9a^2b-4ab^2 => \\ 2a^2b-5a^2b+9a^2b+3ab^2+6ab^2-4ab^2 => \\ 6a^2b+3ab^2+6ab^2-4ab^2 => \\ \boxed{6a^2b+5ab^2}$

$\\ b) \\ \left(2x^2+4xy\right)+\left(y^2-2xy\right)-\left(x^2+4y^2-5xy\right)+\left(x^2-y^2\right)=> \\ 2x^2+4xy+y^2-2xy-\left(x^2+4y^2-5xy\right)+x^2-y^2 => \\ 2x^2+4xy+y^2-2xy-x^2-4y^2+5xy+x^2-y^2 => \\ \boxed{2x^2+7xy-4y^2}$

Answer 2

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