Answer:
D. Earthquakes cause rocks to move and open up new areas for nesting.
The correct answer is - A) Permafrost used to be permanent.
The permafrost used to be permanent until recently, so using certain techniques of building on it functioned properly. But with the climate changes that are becoming more and more evident, the permafrost is no longer permanent, but instead, it is either defrosting in some part of year and then forming again, or has been totally absent from some regions in the present.
That has caused changes in the rules governing building on permafrost. The reason for the changes is that the old techniques do not work properly anymore, and the permafrost changes are making change in the landscape, making big damages on the infrastructure in meantime.
The answer you are looking for is x = 0 (or undefined)
To solve for x, you would first combine all the like terms on the right side. To do so, add 2x and 2x to get 4x and add 24 and 2 together to get 26. This will give you 4x + 28 = 4x + 26, which you can now solve.
To find x, you would get the x by itself. However, in doing so you would get 0 or 0x. This is because you would subtract 4x on both sides to cancel out the 4x on the right, but in this case, it will also cancel out the 4x on the left. Thus meaning the answer is 0 or undefined.
I hope this helps!
