Question

помогите плиз алгебра 7 класс

Answer 1

б)
$\frac{a^{3n-1}b^{n+1}-4a^{n-1}b^{n+1}}{4a^nb^{n-1}-4a^{2n}b^{n-1}+a^{3n}b^{n-1}}=\frac{b^{n+1}(a^{3n-1}-4a^{n-1})}{b^{n-1}(4a^n-4a^{2n}+a^{3n})}=\\=\frac{b^{n+1-(n-1)}*a^{n-1}(a^{2n}-4)}{a^n(4-4a^n+a^{2n})}=\frac{b^2*a^{n-1-n}(a^n-2)(a^n+2)}{(a^n-2)^2}=\\=\frac{b^2*(a^n+2)}{a*(a^n-2)}$


a)
$\frac{x^{3n}-x^ny^{2n}}{3x^{3n}+6x^{2n}y^n+3x^ny^{2n}}=\frac{x^n(x^{2n}-y^{2n})}{3x^n(x^{2n}+2x^ny^n+y^{2n})}=\frac{(x^n-y^n)(x^n+y^n)}{3(x^n+y^n)^2}=\frac{x^n-y^n}{3(x^n+y^n)}$