Answer:
4x+45=2x+61
X=8
Step-by-step explanation:
Since Christopher already has 45 books, this is constant. Similarly, Jeffrey having 61 books implies this is constant. Using the concept of y=mx+c, the above figures are c since they don't change. Therefore, for the case of Christopher, m is 4 and let x represent the number of months. The equation relation to the total number of books Christopher will have after x months will be 4x+45. Similarly, for Jeffrey the equation will be 2x+61 and the time when they have same number of books then the equations are same. Therefore, 4x+45=2x+61 and rearranging similar terms 2x=16 hence x=16/2=8
