How do i figure this out. It's confusing.

If the public debt of a country in 2009 was $10432000000000 and the budget for 2010 was in deficit by $201645000000, what was the public debt in 2010? do not include commas in your answer.

What is the value of  y  in the solution to the system of equations? x  +  y  =  12x  –  3y  =  –30a. –8b. –3c. 3d. 8

Noor brought 21 sheets of stickers. she gave 1/3 of a sheet to each of the 45 students at recess. she wants to give teachers 1 1/2 sheets each.