Answer:
a) the gradient of the linear graph is: 
b) the y-intercept of linear graph is -1
Step-by-step explanation:
a) Find the gradient of the linear graph.
The formula used to find gradient is same as slope

Take any 2 points from the graph.
I will take: (-3,0) and (0,-1)
Putting values in formula and finding gradient

So, the gradient of the linear graph is: 
b) Find the y-intercept of linear graph
The y-intercept of linear graph is the value of y at the point where the line crosses the y axis.
So, in the given graph, that point is -1
So, the y-intercept of linear graph is -1