Ok
The supplement of 141°
The addition of Supplementary angles equals 180°
180 = 141 + x
Solve for x
x = 180 - 141
x = 39
The complement
x + y = 90°
Substitution
39 + y = 90
Solve for y
y = 90 - 39
y = 51°
Result:
The complement of the supplement of 141° = 51°