Question

2. Выполните действия: a) 3/a + (a - 3)/(a + 5) ; (3x ^ 2)/(x ^ 2 - 9) - (3x)/(x + 3)​

Answer 1

Ответ:

1) 3/a +(a-3)/(a+5)=(3*(a + 5) + a(a - 3))

/a (a+5)= (3a + 15 +a/2- 3a) /a(a + 5)=

=(a/2 + 15)/a(a+5)

2) (2x/2)/(x/2-4) - 2x/(x+2)=(2x/2-

2x(x-2))/(x/2-4)=

=(2x/2 - 2x/2 + 4x)/(x/-4)=4x/(x/2-

4)

3) 7a/(a-b)-7=(7a - 7(a - b))/(a-b)=(7a-

7a + 7b)/(a-b)=7b/(a-b)