Answer: 0.0042
Step-by-step explanation: The number shown here, 
 
 
 
 
 , is written in scientific notation since it's compose of a decimal between 1 and 10, in this case 4.2, and a power of ten, in this case
, is written in scientific notation since it's compose of a decimal between 1 and 10, in this case 4.2, and a power of ten, in this case 
 .
.
To write 
 
 
 
 
 in standard notation, we first begin with 4.2.
 in standard notation, we first begin with 4.2.
Next, we look at the exponent, which in this case is -5.
A negative exponent means that we move the decimal point to the left.
This gives us .000042 or 0.000042.