Question

Answer 1

`a)E=(2x+3)^2-2(2x+3)(2x+5)+(2x+5)^2`

   `E=4x^2+12x+9-(4x+6)(2x+5)+4x^2+20x+25`

   `E=4x^2+12x+9-8x^2-20x-12x-30+4x^2+20x+25`

   `E=4`

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`b)F=(x^2+x+1)(x^2-x+1)-(x^2-1)`

   `F=x^4-x^3+x^2+x^3-x^2+x+x^2-x+1-x^2+1`

   `F=x^4+2`

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`c)G=(a+b-c)^2+(a-b+c)^2-2(b-c)^2`

   `G=a^2+b^2+c^2+2ab-2ac-2bc+a^2+b^2+c^2-2ab+2ac-2bc-2b^2+4bc-2c^2`

   `G=2a^2`

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`d)H=(a+b+c)^2+(a-b-c)^2+(b-c-a)^2+(c-a-b)^2`

   `H=a^2+b^2+c^2+2ab+2ac+2bc+a^2+b^2+c^2-2ab-2ac+2bc+a^2+b^2+c^3-2bc-2ab+2ac+a^2+b^2+c^2-2ac-2bc+2ab`

   `H=4a^2+4b^2+4c^2`