Solve the calculation problem, simplify the evaluation (- y). (y + 2x) - (2Y + x). (2y-x) when x = 1, y = 2 (a + 2b). (a-2b) - 2 (2a + b). (2a-b) when a = 1, B = 2 | Math enthusiast | Mathematical art

Solve the calculation problem, simplify the evaluation (- y). (y + 2x) - (2Y + x). (2y-x) when x = 1, y = 2 (a + 2b). (a-2b) - 2 (2a + b). (2a-b) when a = 1, B = 2

（-y）.（y+2x）-（2y+x）.（2y-x）
=(x-y-x)(x+y+x)-4y^2+x^2
=x^2-(y+x)^2-4y^2+x^2
=2-9-16=-23
simple form
=a^2-4b^2-8a^2+2b^2
=-7a^2-2b^2
=-7-8=-15

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