13. Supplementary angles are two angles that add up to 180 degrees.
3x + x = 180
Combine like terms:
4x = 180
4x divided by 4 = x
180 divided by 4 = 45
x = 45
Equation:
3(45) + 45 = 180
135 + 45 = 180 (TRUE STATEMENT)
Angle A = 135 degrees
Angle B = 45 degrees
This is correct as 135 + 45 adds up to 180 (making it a supplementary angle) AND 135 is 3 times bigger than 45 so it fits the answer’s standard.
Ima do number 14 in the comments as I don’t want to take too long to show number 13.