In a newspaper, it was reported that yearly robberies in Springfield were up 50% to 351 in 2013 from

In a newspaper, it was reported that yearly robberies in Springfield were up 50% to 351 in 2013 from 2012. How many robberies were there in Springfield in 2012?

Let the robberies in 2012 be r. We're given the following equation:
1.5r = 351 <-- We write a 50% increase as 1.5

To solve this equation for r, we type it into our search engine and we get:
r = 234