Answer:
a.) 
Step-by-step explanation:

Find two numbers that add up to -6 and multiply to -40 (you will most likely need a negative and a positive because -40):
-10 and 4
Factor:

Finito.
0.09
one tenth of 0.9 is 0.9 divided by 10, which means moving the decimal point one place to the left
= 0.09
We have to find out the coordinates of two points to find out the slope.
according to the figure,
first point is x1 = 1 & y1 = 2
second point is x2 = 4 & y2 = 1
slope = (y2 - y1) / (x2 - x1)
= (1-2) / (4-1)
= -1 / 3