Both A and C are used within this problem. Distributing happens in the first and second step. Also, Inverse operations are used in nearly every step that is solving.
$68.60 would be the correct answer
Answer:
28
Step-by-step explanation:
because in this series the gap between number is gradually increasing from 1 and so this times its the turn of number 7 so 21+ 7 = 28
b^2-4ac<0 b^2-144<0 (b-12)(b+12)<0
-12<b<12
