Answer:
y = -x + 7
Explanation:
As we move from (8, 0) to (0, 8), we see x decreasing by 8 ('rise') and y increasing by 8 ('run'). Thus, the slope of this line is m = rise/run = 8/(-8) = -1.
Starting from y = mx + b and substituting 8 for x, 0 for y and -1 for m, we get:
0 = -1(8) + b, or b = 8
Then the equation of the line through the two given points is y = -x + 8. Any line parallel to this one has the same slope: m = -1.
Repeat the above work to find the y-intercept of the line parallel to y = -x + 8 that goes through (2, 5):
5 = -2 + b, or b = 7
Then the desired line (final answer) is y = -x + 7