Question

Помогите номер 11 и номер 13, срочно

Answer 1

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Answer 2

$- sqrt{7}t ( sqrt{14} tz- sqrt{21} t^{2} z^{3})=- sqrt{98} t^{2} z+ sqrt{147} t^{3} z^{3} \(2x-3y)(5x+7y-1)=10 x^{2} +14xy-2x-15xy-21 y^{2} +3y=10 x^{2} -xy-2x-21 y^{2} +3y\   (a-b)( a^{2} +ab+ b^{2} )= a^{3} + a^{2} b+a b^{2} -b a^{2}-a b^{2} - b^{3}=a^{3} - b^{3}\(x+1)( x^{2} -x+1)=  x^{3} - x^{2} +x+ x^{2} -x+1=x^{3} +1$