Question

сократить дробь, 8,9СРОЧНО ДАМ 35 БАЛЛОВ​

Answer 1

$8)\ \ \dfrac{b^7-b^{10}}{b^9-b^3}=\dfrac{b^7\, (1-b^3)}{b^3\, (b^6-1)}=\dfrac{b^4\, (1-b)(1+b+b^2)}{(b^2-1)(b^4+b^2+1)}=\dfrac{b^4(1-b)(1+b+b^2)}{(b-1)(b+1)(b^4+b^2+1)} =\\\\\\=-\dfrac{b^4\, (1+b+b^2)}{(b+1)(b^4+b^2+1)}$

$9)\ \ \dfrac{c^6-c^4}{c^3+c^2}=\dfrac{c^4\, (c^2-1)}{c^2(c+1)}=\dfrac{c^2\, (c-1)(c+1)}{c+1}=c^2\, (c-1)$