This figure shows y=f(x), the graph of the function f. If the function g is defined as g(x)= 2•f(x)-1, what is the value of g(1)?

This is a nice twist to see if you can read the graph and interpret what it means.
f(1) is the y value of the graph when x = 1
So start at x = 1 and find the y value. Go straight up. The point you reach is (1,3)
so g(1) = 2*f(1) - 1
g(1) = 2*3 - 1
g(1) = 5
Answer
g(1) = 5