18 The 2 trapezia formed by midpoint are similar so we can write
19/24 = x / 19
x = 19^2 / 24 = 15.04
19. 360 degrees . This is true for all polygons
18 is the answer //////////////////
Answer:

Step-by-step explanation:
5^2x=7^x+1 ⇔ ln5^2x = ln7^x+1 ⇔ 2xln5 = (x+1)ln7 ⇔ (2ln5-ln7)x = ln7
⇔ x = ln7/(2ln5-ln7)