Answer: \(46.44\times10^{11}\)
Step-by-step explanation:
Given multiplication problem
\((6.45\times10^6)\cdot720,000\)
Here, 720,000= \(7.2\times10^5\)
Thus, the given problem becomes
\((6.45\times10^6)\cdot7.2\times10^5\)
\(=6.45\times10^6\cdot7.2\times10^5\\=6.45\times7.2\times10^{6+5}..............[\text{by law of exponents }a^ma^n=a^{m+n}]\\=46.44\times10^{11}\)
