What is the value of $4^{3}-3^{2}+6^{2}-5^{2}+8^{2}-7^{2} ?$

What will come in the place of the question mark $(?)$ in the following equation?
$(21)^{2} - 3717 \div 59 = ? \times 8$

If $m^{n} = 169$,what is the value of $(m+1)(n-1)$?

The value of $\frac{1.073 \times 1.073 - 0.927 \times 0.927}{1.073 - 0.927} + \frac{(3^4)^4 \times 9^6}{(27)^7 \times 3^9}$ is

If $a^{2}+b^{2}+\frac{1}{a^{2}}+\frac{1}{b^{2}}=4,$ then the value of $a^{2}+b^{2}$ will be

What approximate value will come in place of the question mark $(?)$ in the given equation? (You are not expected to calculate the exact value)
$24.98^{2} \times \frac{16.02^{2}}{(7.98 \times 15.04)} \times 38.93 = 130 \times ?^{2}$