Me
12 pens and 5 rulers cost $61 while 3 pens and 10 rulers cost $59.
find the price of each pen and ruler.
let x and y be the price of the pen and ruler respectively.
use the fact that 12 pens and 5 rulers cost $61 to set up equation 1.
write the equation in the form ax + by = 0, where a is positive.