An arithmetic sequence is represented by the function f(n) = 5 + 2(n-1). What is the first term of the sequence?

Idon’t understand this.. will someone ? will mark brainliest along with 20 points.

The graph shows the distance y, in inches, a pendulum moves to the right (positive displacement) and to the left (negative displacement), for a given number of seconds x. how many seconds are required for the pendulum to move from its resting position and return? enter your answer in the box.

X+ y = 5 ; x - y =3 solve using linear combination