Fill in the blanks to make a true equation:

Are the 2 blanks equal or not?

\(1/n(n+3)=blank/n+blank/n+3. \)

1/ [n (n + 3)] = A / n  + B /(n + 3)

Multiply through by  n (n + 3)

1 =  A ( n + 3)  + B(n)

1 = (A + B)n  + 3A

Equate terms

A + B  = 0

3A   =1  →  A =1/3

So B = -1/3

Check     

(1/3) / n   - (1/3) / ( n + 3)  =

[(1/3)(n + 3)  - (1/3) n] / (n (n + 3))

[ (1/3 n  + 1  - 1/3 n ]  / [n ( n + 3)]  = 

1 / [ n ( n + 3) ]

So

first blank = 1/3

second blank  =  -1/3

Thanks CPhill for covering up for me