ANSWER

EXPLANATION
The given line passes through;
(-1,-1) and it is parallel to x + y = 3.
This line given to us can be rewritten as
y=-x+1
It has slope m=-1.
The line parallel to this line also has slope m=-1.
We obtain the equation of the line using the formula:

We substitute the slope and the point to obtain:



The equation of the line is

Heather winning, so the probability that Isabelle will win is : 1 whole right ?
16/81 = 65 over 81
The combined measure is 180 degrees