What is the simplest form for five fifths? quick plz

What is the effect on the graph of the parent function f(x) = x when f(x) is replaced with 3f(x)? a) shifts the line 3 units up b) shifts the line 3 units down c) increases the slope of the line by a factor of 3 d) decreases the slope of the line by a factor of 3

Which of those sequences is a geometric sequence

Solve the system of equations y= 3/2 - 1, -x+ y =-3