Whats the answers to each number? due tomorrow morning

1: -16+(-8)

2: (-4)-7

3: -)

4: 6.25+(-8.50)

5: 10..4)

6: -54.26+(-15.42)

7: -1 1/2 + 2 7/10

8: 5/8- (-1 7/8)

9: 1/4-7/8

Two planes leave an airport at the same time, one flying east, the other flying west. the eastbound plane travels 20 mph slower. they are 1600 mi apart after 2 hr. find the speed of each plane.

Ammonia molecules have three hydrogen atoms and one nitrogen atom. how many of each atom arein five molecules of ammonia

Which is the correct first step in finding the area of the base of a cylinder with a volume of 26x cubic meters and a height of 6.5 meters? v=bh 6.5=b(26x) v=bh v=26pi+(6.5) v=bh v=26pi(6.5) v=bh 26pi=b(6.5)