Question

разложите на множители

Answer 1

$100x^4-81x^2y^4=x^2(100x^2-81y^4)=x^2((10x)^2-(9y^2)^2)=\\x^2(10x+9y^2)(10x-9y^2)$
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$a^2-6a+9-4b^4=a^2-2*a*3+3^2-2^2(b^2)^2=(a-3)^2-(2b^2)^2=\\((a-3)+2b^2)((a-3)^2-2b^2)=\\(a-3+2b^2)(a-3-2b^2)$
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$25x-x^3=0$
$x(25-x^2)=0$
$x=0;x_1=0$
$25-x^2=0$
$x^2=25$
$x_2=sqrt{25}=5;$
$x_3=-sqrt{25}=-5$
отвте: -5;0;5