Which of the following expressions is not correctly written in scientific notation?

1 × 10 4
10 × 10 7
9 × 10 2
5 × 10 3

If a flying disk is 139 meters in the air and travels at an average of 13 m/s how long is it in the air

If the tip varies directly with the number of guest which equation represents between the tip,t, and the number of guest,g?

Ben works in his dads bakery packing bagels each package can have no more then 16 bagels 3/4 of the bagels in each package are plain what other fractions could represent the part of the bagels in each package that will be plain