Writing equations II

This task is about writing maths equations to describe practical situations.
Complete the sentences below by writing an equation in the spaces provided.

a)
Ihaka had n mice in a cage. He bought another 7 mice to make a total of 12 mice altogether.
 
An equation for this is ______________________ (where n is the number of mice Ihaka started with.)
 

b)
Anushka started with n dollars. One week later she had 4 times this amount. She then had $36.00.
 
An equation for this is _________________________ (where n is the amount of money Anushka started with.)
 

c)
Harata had 20 chocolates. She gave an equal number of chocolates to 3 friends and had 2 chocolates left over.
Each friend got n chocolates.
 
An equation for this is _________________________ (where n is the number of chocolates each friend got.)
 

d)
Carl had some sheep in 7 pens with n sheep in each pen. When 5 sheep were sold, Carl had 86 sheep left.
 
An equation for this is _________________________ (where n is the number of sheep in each pen.)