How do you solve this chemistry problem? Need HELP?

I need help with how to solve a math problem.?

• I am not interested to the actual answer to the problem, only how to go about answering it, though I will post the particular numbers in the problem.. You see, I wish to understand how to figure out when variable A will surpass variable B over a length of time. I want to know exactly how much time. Variable A is currently at a number represented by let's say, 147,946, while variable B is currently at let's say, 578,268. Variable A increases at a rate of about 4351.34 units a day. Variable B increases at a rate of about 1250.308 units a day. How many days would it take before Variable A surpasses Variable B in number of units? Again, I only wish to know HOW to solve the problem, so I may solve this problem, and future problems of this kind, by myself. Thank you!

• Answer:

  rate X Time = variable A Rate X time= variable B so the point were they meet is A/rate= B/rate. so which ever is going faster or whatever will surpass at this point in time. The general rule is that if two equations share a variable or constant, you can substitute. time=time so (rate x time)= (rate x time)