You use FOIL (first, outer, inner, last) to check your answer. Eg: (x-4)(x+3)then distribute by using FOIL to get 2 2
x +3x -4x -12 then simplify to get x -x -12
Step-by-step explanation:
when we get the common ratio that must be equal
r=6/2=18/6=54/18=3 equal
So it is geometric
By using this equation:
a(n)=a(1)*r^(n-1)
and we have a(1)=2 , r=3
Explicit rule: a(n)=2*(3)^(n-1)
hope this helps