7000000000
It means that you need to multiply 7 by 10, 9 times.
So just add 9 zeros to 7.
Answer is in a photo. I can only upload it to a file hosting service. link below!

Answer:
2x(6x+1)
big rectangle - small rectangle = shaded region
Hi there!
When a segment is tangent to a circle, it is perpendicular to the radius. If you're given measurements, like the image below, you can use the pythagorean theorem to determine if the triangle is a right triangle. If the triangle is right, then the segment is tangent to the circle.
Hope this helps!! :)
If there's anything else that I can help you with, please let me know!