Can you see why?
I don't even know where to start with the first step.1. Write down the range of values of x for which the graph of y = f(x) has a negative gradient.
They're talking about a tangent line, yes? So where do I draw it?2. The equation f(x) + x – 1 = 0 can be solved by drawing a line on the grid.
(i) Write down the equation of this line. 
(ii) How many solutions are there for f(x) + x – 1 = 0?
"...graph of y = f(x) has a negative gradient. " There's only one negative slope, so the answer is the start and end values of the slope on the x-axis. The slope starts at (0,3) and ends at (6,-9) so the answer is 0 and 6. Is my reasoning right?