Question

Write the equation through (2,5) parallel to the line through (8,0) and (0,8)

Answer 1

Answer:

y = -x + 7

Step-by-step 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