Alright now combine all like terms remember no matter what you can allways add like terms ok now it would be 5-3 you should get two now add the n and the squared 2 and 2n2 should be your answer witch is A
Now for the other equation 8+-4 =4 3b +6b = 9b now drag the 2c down and you get
4+9b-2c I hope this helps you