Help please!!

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

What is the y-intercept of the line given by the equation

What is coefficient of the term of degree of degree 5 in the polynomial below