To subtract two numbers in scientific notation, they must first have the same exponent. Here's how to do that step-by-step using the numbers \( 1.95 \times 10^6 \) and \( 3.2 \times 10^4 \).
Step 1: Write the numbers
- \( A = 1.95 \times 10^6 \)
- \( B = 3.2 \times 10^4 \)
Step 2: Adjust the exponent of \( B \) to match \( A \)
Since \( A \) has the exponent of \( 10^6 \), we need to convert \( B \) from \( 10^4 \) to \( 10^6 \).
To convert \( 3.2 \times 10^4 \) to a base of \( 10^6 \): \[ B = 3.2 \times 10^4 = 3.2 \times 10^4 \times \frac{10^2}{10^2} = 3.2 \times 10^6 \div 100 = 0.032 \times 10^6 \]
Step 3: Subtract the numbers
Now that both numbers have the same exponent, we can subtract: \[ A - B = (1.95 \times 10^6) - (0.032 \times 10^6) \]
Calculating: \[ = (1.95 - 0.032) \times 10^6 \] \[ = 1.918 \times 10^6 \]
So the final answer for the subtraction of \( 1.95 \times 10^6 \) and \( 3.2 \times 10^4 \) is: \[ \boxed{1.918 \times 10^6} \]