$100 at 7% for 6 years

The triangles are similar. what is the value of x? show your work.

12. the amount of money in a bank account decreased by 21.5% over the last year. if the amount of money at the beginning of the year is represented by ‘n', write 3 equivalent expressions to represent the amount of money in the bank account after the decrease?

What is the name used to describe a graph where for some value of x, there exists 2 or more different values of y?