To find how much the U.S. national debt increased from 1971 to 2021, we will subtract the 1971 debt from the 2021 debt.
Given:
- National debt in 2021 = \(2.9617 \times 10^{13}\)
- National debt in 1971 = \(3.98 \times 10^{11}\)
First, we need to express both values in the same exponent for easier subtraction. We can rewrite \(3.98 \times 10^{11}\) in terms of \(10^{13}\):
\[ 3.98 \times 10^{11} = 0.0398 \times 10^{13} \]
Now, we can subtract the two values:
\[ \text{Increase in debt} = (2.9617 \times 10^{13}) - (0.0398 \times 10^{13}) \]
Now perform the subtraction:
\[ \text{Increase in debt} = (2.9617 - 0.0398) \times 10^{13} = 2.9219 \times 10^{13} \]
Thus, the increase in the U.S. national debt over the 50-year period is \(2.9219 \times 10^{13}\).
So the answer is:
$2.9219×10^{13}$.