Question

Сократите дробь:
1)3a-9/a^2-9=
2)81n^2-64m^2/81n^2-144nm+64m^2=
3)x^4-16/x+2=

Answer 1

1)$frac{3a^{2}-9}{a^{2}-9}=frac{3(a-3)}{(a-3)(a+3)}=frac{3}{a+3}$

 

2)$frac{81n^{2}-64m^{2}}{81n^{2}-144mn+64m^{2}}=frac{(9n-8m)(9n+8m)}{(9n-8m)^{2}}=frac{9n+8m}{9n-8m}$

 

3)$frac{x^{4}-16}{x+2}=frac{(x-2)(x+2)(x^{2}+4)}{x+2}=(x^{2}+4)(x-2)$