Answer:
2x+9 when x equals 3 is 2*3+9
=15
Explanation:

Answer:
The correct answer is: A) Asteroid belt.
Explanation:
All of the other events can be explained by colliding worlds in the early solar system but the asteroid belt can't. The asteroid belt originated from the primitive solar nebula as a congregation of planetesimals, which were the precursors of the protoplanets.
Answer:
A. True
Explanation:
Although convection in the asthenosphere is widely accepted as the cause of plate movements, it may be that the weight of down-going lithosphere in subduction zones pulls the trailing plate behind it. This is true because plates at our planet's surface move because of the intense heat in the Earth's core that causes molten rock in the mantle layer to move, It moves in a pattern called a convection cell that forms when warm material rises, cools, and eventually sink down.