Is 0.0000734 standard notation or scientific notation ?

Which number produces a rationale number when multiplied by 1/5

The difference of three and the reciprocal of a number is equal to the quotient of 20 and the number. find the number.

Two poles, ab and ed, are fixed to the ground with the of ropes ac and ec, as shown: what is the approximate distance, in feet, between the two poles? 6.93 feet 8.66 feet 12.32 feet 15.59 feet