I'll solve 21, and you then should be able to solve the rest on your own!
Since ADC is 135, that means that that whole angle is 135 degrees. In addition, since angles ADB and BDC add up to ADC, we get ADB+BDC=ADC=135=11x+9+7x=18x+9. Subtracting 9 from both sides, we get 126=18x. Dividing both sides by 18, we get x=7. Plugging that into 11x+9=BDC, we get 11*7+9=77+9=86
The answer to this question is D
A) One solution: 5x +2y = 0 . . . . (any line with a different slope)
b) Two solutions: not possible
c) No solutions: 5x -2y = 0 . . . . (any different line with the same slope)
d) Infinitely many solutions: 10x -4y = 6 . . . . (any other equation for the same line)
Answer:
Step-by-step explanation: