In order to find the solution for the equation y = 13 -x, you must put each of the values of x and y coordinates from points a, b, c, and d to check which point satisfies the equation.
Lets try it now:
(Put the value of x coordinate in place of x and the value of y coordinate in the place of y like shown below)
y = 13 - x
For point a(-1, 12), y = 12 and x -1
so 12 = 13 - (-1) = 14 ---> this is wrong
for point b(3, 10)
10 = 13 - 3 = 10 (WOW, you found your answer so there is no need to do any further calculations!)
Option b.(3, 10) is the solution to the equation y = 13 - x
