Answer:
∠ B = 54°
Step-by-step explanation:
The angles are supplementary, that is they sum to 180° , then
7x + 14 + 5x - 26 = 180 , that is
12x - 12 = 180 ( add 12 to both sides )
12x = 192 ( divide both sides by 12 )
x = 16
Then
∠ B = 5x - 26 = 5(16) - 26 = 80 - 26 = 54°
