Who can solve this ?

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 statements about these triangles is true

Nine more than four times a number is the same as one less than twice the number. find the number?