If m angle abc=180. what is the degree measure of angle adc

if ∠ABC = 180°,

then, 2x∠ADC = ∠ABC ( angles subtended by an arc at the center is double the angle subtended it at any point on the remaining part if the circle)

{ please read the theorem carefully as i know u wont be able to understand it at first try :) }

therefore ∠ADC = 90°

the answer will be b x² +x-1

step-by-step explanation: