\( \Large \left(70 \div 100\right)^{?+3} = \left(0.49\right)^{4} \times \left(0.343\right)^{4} \div \left(0.2401\right)^{4} \)
\( \Large \left(0.7\right)^{?+3} = \left(\frac{0.49 \times 0.343}{0.2401}\right)^{4} \)
\( \Large \left(0.7\right)^{?+3} = \left(0.7\right)^{4} \)
On comparing the exponents both sides, we get
? + 3 = 4
Therefore, ? = 4 - 3 = 1