Плезааун (упростите плиз)

Question

Плезааун (упростите плиз)

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Answer 1

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Answer 2

3y(6y+2x)-(x+3y)^2=18y^2+6xy-(x^2+6xy+9y^2)=18y^2+6xy-x^2-6xy-9y^2=9y^2-x^2
-10ab+5(a+b)^2= -10ab+5(a^2+2ab + b^2)=-10ab+5a^2+10ab+5b^2=5a^2+5b^2