You just divide them, let me know if you want the actual answers, but these are all just dividing
How many grandchildren do they have?
Answer:
x = 
Step-by-step explanation:
Given
3x + k = c ( isolate the term 3x by subtracting k from both sides )
3x = c - k ( divide both sides by 3 )
x = 
Last answer for the first question and in not sure about the second one
Answer:
5
Step-by-step explanation: