How do you solve am= n over p for a

Ineed with number 17 i don’t get it at alll

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

Alicia puts $400 in a bank account. each year the account earns 5% simple interest. how much money will be in her bank account in six months?