Answer:
17.7
Step-by-step explanation:
This figure is a pentagon - a shape with 5 sides. In a pentagon, the figure's angles add to 540.
100 + 7x-4 + 3x + 23 + 9x - 6 + 90 = 540
190 +19x + 13 = 540
203 + 19x = 540
19x = 337
x = 17.7
