I'm pretty sure it's a prime number.
Answer:
128
Step-by-step explanation:
Supplementary means they sum to 180, and it's also a straight line. 180-49 = 131. 131-3 = 128, or x.
Answer:
B
Step-by-step explanation:
the supplement is the angle that will add to the other angle to get 180 degrees. 180-129=51 which is B.
Answer:
x = 7
Step-by-step explanation:
Similar figures have sides that are proportional. Setting up a proportion for the sides of the figures will help solve for 'x':

Cross-multiply: 3(x + 1) = 6(x - 3)
Distribute: 3x + 3 = 6x - 18
Combine like terms: 21 = 3x
Solve for 'x': x = 7