I believe its -1 because x2-x1/y2-y1 good luck
Answer:
∠ ABC = 116°
Step-by-step explanation:
Since the angles are supplementary, they sum to 180° , that is
8x - 36 + 4x - 12 = 180
12x - 48 = 180 ( add 48 to both sides )
12x = 228 ( divide both sides by 12 )
x = 19
Then
∠ ABC = 8x - 36 = 8(19) - 36 = 152 - 36 = 116°
Look at the picture.
ΔABD and ΔBCD are similar, therefore:

Use Pythagorean theorem:
When you subtract the exponents you get p-². You have to put it under 1 to get the positive exponent, which gives 1/p².