How do I balance these equations?

Which is an equation for the nth terms of the sequence 12,15,18,21

In the sixth grade 13 out of 20 students have a dog if there are 152 sixth grade students how many of them have a dog

Bo is buying a board game that usually costs bb dollars. the game is on sale, and the price has been reduced by 18\%18%. which of the following expressions could represent how much bo pays for the game? choose 2 answers: choose 2 answers: (choice a) a 0.82b0.82b (choice b) b 1.18b1.18b (choice c) c b-0.18b−0.18 (choice d) d b-18b−18 (choice e) e b-0.18bb−0.18b