To compute the expression \((7.0 \times 10^{28}) \times (-3.2 \times 10^{-20}) \times (-6.4 \times 10^{35})\), we can first handle the coefficients and the powers of 10 separately.
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Coefficients:
- \(7.0 \times -3.2 \times -6.4\)
- \(7.0 \times -3.2 = -22.4\)
- \(-22.4 \times -6.4 = 143.36\)
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Powers of 10:
- \(10^{28} \times 10^{-20} \times 10^{35}\)
- \(10^{28 + (-20) + 35} = 10^{28 - 20 + 35} = 10^{43}\)
Now, combine the results:
\[ 143.36 \times 10^{43} \]
To express this in standard scientific notation, we convert \(143.36\) to \(1.4336 \times 10^2\):
\[ 143.36 \times 10^{43} = 1.4336 \times 10^2 \times 10^{43} = 1.4336 \times 10^{45} \]
Thus, the final result of \((7.0 \times 10^{28}) \times (-3.2 \times 10^{-20}) \times (-6.4 \times 10^{35})\) is:
\[ \boxed{1.4336 \times 10^{45}} \]