Answer:
Shifts f(x) 3 units upward -> f(x)+3
Shifts f(x) 3 units left -> f(x+3)
Compresses f(x) by a factor of 1/3 towards the y-axis -> f(3x)
Stretches f(x) by a factor of 3 away from the x-axis -> 3f(x)
Explanation:
To help understand this, try graphing a simple function, say f(x)=y=x^2. Now try x^2+3, (x+3)^2, (3x)^2, and 3(x^2). See how this affects the function.