Question

PLZ HELP 100 PTS!!!!!!!!!!!!!!!!!

Answer 1

Answer:

x = 12

Step-by-step explanation:

The mistake made here is in making 130 = 9x + 7. They are not the same.

The central angle = 130 degrees.

Any angle sharing the endpoints of the central angle and having it's vertex on the same side of the central angle is 1/2 the central angle.

1/2 the central angle = 130 /2 = 65

Cyclic quadrilaterals (those with all 4 points touching a circle's circumference) have opposite angles  supplementary.

65 + 9x + 7 = 180           Combine like terms on the left

72 + 9x = 180                 Subtract 72 from both sides

72 - 72 + 9x = 180-72     Combine

9x = 108                          Divide by 9

9x/9 = 108/9                  

x = 12

 

Answer 2

Answer:

CORRECT ans is x=12

Step-by-step explanation:

mAC=130

mAC is the central angle = 2 * inscribed angle, <ABC

2 * <ABC=130

<ABC=65

ABCD is an inscribed quadrilateral so its opposite angles are supplemental

<ABC + <ADC=180

65+9x+7=180

9x=108

x=12