There are 14 floors in the building, because since Juan went up 4 floors, down 3 floors, and up one floor; so we know that he is 2 floors above from where he originally started. Once he went down 9 floors he passed the starting point and went to the bottom of the building. So, the middle must have been the 7th floor. Once I knew that I multiplied 7*2 and it got me 14. So in total there are 14 floors. I hope this helped ^^
1)-8(-2x+6)+(-10)
16x-48-10
16x-50
2) 9(x-8)-17x
9x-72-17x
-8x-72
First, you multiply 4 by 1. Then that's your answer, 4. I hope it helped!