Question

докажите тождества (х^3-9у^4)^2п(х^3+9у^4)^2+36х^3(у^4-х)=-36х^4
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Answer 1

$\displaystyle \tt (x^3-9y^4)^2-(x^3+9y^4)^2+36x^3(y^4-x)=-36x^4\\(-18y^4)\cdot2x^3+36x^3y^4-36x^4=-36x^4\\\displaystyle \tt -36x^3y^4+36x^3y^4-36x^4=-36x^4\\\displaystyle \tt \underline{\bold{-36x^4=-36x^4}}$