Answer:
Step-by-step explanation:
9.
Sum of angles in triangle:
90 + 3x + 11 + 25 = 180
Add like terms:
126 + 3x = 180
Subtract 126 on both sides:
3x = 54
Divide:
x = 18
11.
Supplementary angles:
45 + 3x = 180
Subtract 45:
3x = 135
Divide 3:
x = 45
