A linear pair is a pair of angles that form a line. And since they form a line, when added, they equal 180.
x = one angle....y = the other one
x + y = 180
x = y + 26
time to sub
y + 26 + y = 180
2y + 26 = 180
2y = 180 - 26
2y = 154
y = 154/2
y = 77 <=== this is one angle
x = y + 26
x = 77 + 26
x = 103 <=== and the other one