To find out how much farther Neptune is from Earth than Mars, we need to subtract the distance from Earth to Mars from the distance from Earth to Neptune.
Given:
- Distance from Earth to Mars = \( 2.25 \times 10^8 \) km
- Distance from Earth to Neptune = \( 4.3514 \times 10^9 \) km
Now, we can perform the subtraction:
\[ \text{Distance from Earth to Neptune} - \text{Distance from Earth to Mars} = 4.3514 \times 10^9 , \text{km} - 2.25 \times 10^8 , \text{km} \]
To perform this subtraction, we need to express both numbers with the same exponent. We convert \( 2.25 \times 10^8 \) km to a form with \( 10^9 \):
\[ 2.25 \times 10^8 , \text{km} = 0.225 \times 10^9 , \text{km} \]
Now we can subtract:
\[ 4.3514 \times 10^9 , \text{km} - 0.225 \times 10^9 , \text{km} = (4.3514 - 0.225) \times 10^9 , \text{km} \]
Calculating the subtraction:
\[ 4.3514 - 0.225 = 4.1264 \]
So,
\[ 4.1264 \times 10^9 , \text{km} \]
Thus, the distance from Earth to Neptune is \( \boxed{4.1264 \times 10^9} \) km farther than the distance from Earth to Mars.