Answer
$2KOH(aq) + NiSO_4(aq) --> Ni(OH)_2(s) + K_2SO_4(aq)$
Work Step by Step
1. Write the unbalanced equation:
$KOH + NiSO_4 --> Ni(OH)_2 + K_2SO_4$
2. Balance the equation:
Start fixing the number of K atoms, by multiplying KOH by 2:
$2KOH + NiSO_4 --> Ni(OH)_2 + K_2SO_4$
Now the equation is totally balanced.