Which of the following expressions is written in scientific notation?
a)73.4*10^5
b)0.09*10^7
c)80*10^3
d)4.22*10^(–3)
what is exactly scientific notation?

Rick is driving to his uncles house in greenville,which is 120 miles from ricks town .after covering x miles rick she's a sign stating that greensville is 20 miles away. which equation when solved will give the value of x. a: x+120 = 20 b: x x120 =20 c: x +20 equals 120 d: x x20= 120