Vlad spent 20 minutes on his history homework and then completely solved x math problems that each took 2 minutes to complete. What is the equation that can be used to find the value of y, the total time that Vlad spent on his homework, and what are the constraints on the values of x and y?

Question

Vocaloid · Answer

If each math problem takes 2 minutes and he solved (x) problems, then he spend 2*x minutes solving them

Add this onto the 20 he spent on history

Set the sum equal to the total time to get the final equation

As for constraints - what possible values for x are there? Can x be negative, or a fraction? What about y?