Determine the positive number that must be added or subtracted to the expression to complete the square. x ^ 2 - 2x.

Yes i could be the length of the triangle

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?