In the early months of some year one site added 0.4 million new accounts everyday. at this rate, how many days would be needed to add 20 million new

Abari owns 100 shares of stock a and 45 shares of stock b. for the past month, his stocks have been fluctuating inversely. stock a decreased by m cents per share and stock b increased by n cents per share. which equation can be used to find the total change in value of jabari's shares per month?