Please help me with this problem :)

Answer:
d.
Step-by-step explanation:
The red graph is the black one times 2.
So y = 2 f(x). which is the same as y/2 = f(x) (divide by 2).
If you fix a value for x, the y coordinate on the red graph is always twice the y coordinate of the black graph.
So, if f(x) is the equation of the black graph, the red equation will associate twice this quantity for each x value:
[tex]y=2f(x)[/tex]
or, equivalently,
[tex]y=2f(x) \iff \dfrac{y}{2}=f(x)[/tex]