20+x = 12+2x is the answer and x=8
The answer is 81. You just have to do the division in the traditional way.
The recursive formula would be:

This is because the first term, a₁, is 10. A recursive rule is dependent upon the term before it (a(n-1)) and the common ratio. The common ratio, or the number that each term is multiplied by, is -8.
The algebraic expressions can be written as

The given expression is,
Answer: It is because if ∠N and ∠K are congruent and are same in size and shape.