Solve the system of equations by substitution. Write your solution as an ordered pair x+y=81
y=8x

X + 8x = 81
9x = 81, x = 9
y = 8(9), y = 72
Solution: (9, 72)

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?