计算：①2a+3a=5a5a，②ba−cb=b2−acabb2−acab，③（-3b2a）2=9b24a29b24a2，④1x−1y=y−xxyy−xxy，⑤2aa−b+a+bb−a=⑥x2−1(x+1)2＝()x+1；x−1x+1x−1x+1，⑦a2a+3-9a+3=；⑧aa−b+bb−a=．

Question

计算：①(2)/(a)+(3)/(a)=

(5)/(a)

(5)/(a)

，②(b)/(a)−(c)/(b)=

(b2−ac)/(ab)

(b2−ac)/(ab)

，③（-(3b)/(2a)）²=

(9b2)/(4a2)

(9b2)/(4a2)

，④(1)/(x)−(1)/(y)=

(y−x)/(xy)

(y−x)/(xy)

，⑤(2a)/(a−b)+(a+b)/(b−a)=______⑥(x2−1)/((x+1)2)＝(())/(x+1)；

(x−1)/(x+1)

(x−1)/(x+1)

，⑦(a2)/(a+3)-(9)/(a+3)=______；⑧(a)/(a−b)+(b)/(b−a)=______．

Answer 1

①(2)/(a)+(3)/(a)=(5)/(a)，
②(b)/(a)−(c)/(b)=(b2−ac)/(ab)，
③（-(3b)/(2a)）²=(9b2)/(4a2)，
④(1)/(x)−(1)/(y)=(y−x)/(xy)，
⑤(2a)/(a−b)+(a+b)/(b−a)=(2a−a−b)/(a−b)=(a−b)/(a−b)=1；
⑥(x2−1)/((x+1)2)=((x+1)(x−1))/((x+1)2)=(x−1)/(x+1)，
⑦(a2)/(a+3)-(9)/(a+3)=(a2−9)/(a+3)=((a+3)(a−3))/(a+3)=a-3；
⑧(a)/(a−b)+(b)/(b−a)=(a)/(a−b)-(b)/(a−b)=(a−b)/(a−b)=1．
故答案是：(5)/(a)，(b2−ac)/(ab)，(9b2)/(4a2)，(y−x)/(xy)，(x−1)/(x+1)，1，a-3，1．