Answer:
7.81*10^11
Step-by-step explanation:
1.86*10^5=186,000
186,000*4,200,000=7.81*10^11
It is! The correct answer is "C" since there is a 1/8 difference in every fraction.
I hope this helps!

Actually Welcome to the Concept of the Quadrilaterals.
Basically we know that, the sum of opposite angles of a quadrilateral inscribed in a circle is always 180°.
so applying this law here, we get as,
2X + (3X-10) = 180°
=> 5X - 10° = 180°
=> 5X = 190°
=> X = 190°/5
=> X = 38°
thus the angle X= 38°.
When you do the second step it is 40 so you add one zero from the 7200 and thats where you got the zero