Pencils sell for 1.98 per dozen a teacher bought 288 pencils for his math classes. how much did the pencils cost?

Pls! does anybody know a shortcut for answering these types of questions in the future?

How is the equation of this circle written in standard form? x2 + y2 - 6x + 14y = 142 a) (x - 3)2 + (y + 7)2 = 200 b) (x+ 3)2 + (y - 7)2 = 200 (x - 6)2 + (y + 14)2 = 142 d) (x+6)2 + (y- 14)2 = 142

Could someone me with this question i’ve been stuck on it for 20 minutes