The quarters, buckled, and dimes totaled 20 and their value was $2.05. how many kind were there if there were 3 times as many dimes as quarters

We assume the question is intended to say there are a total of 20 quarters, nickels, and dimes, the value of which is $2.05. The number of dimes is 3 times the number of quarters.

Let q, n, d represent the numbers of quarters, nickels, and dimes, respectively. Then you have three equations in the unknowns:
  q +n +d = 20
  25q +5n +10d = 205
  -3q +d = 0

A calculator can give the solution to this matrix equation in short order. It is
  q = 3
  n = 8
  d = 9

There are 3 quarters, 8 nickels, and 9 dimes.


If you use the third equation to write an expression for d, you can substitute that into the other two equations.
  q +n +3q = 20
  25q +5n +10(3q) = 205
Simplifying, these are
  4q +n = 20
  11q +n = 41
Subtracting the first from the second, we find
  7q = 21
  q = 3
From there, it is easy to find d=9, n=8.

This is what i found “an explicit formula designates the nth term of the sequence, as an expression of n (where n = the term's location). it defines the sequence as a formula in terms of n. this example is an arithmetic sequence(the same number, 5, is added to each term to get to the next term).” i hope this you for what your looking for. can you plz mark me brainliest?