Find the value of $?$ satisfying the following equation: $\frac{7.2 \times 7.2 \times 7.2 + 2.8 \times 2.8 \times 2.8}{7.2 \times 7.2 - 7.2 \times 2.8 + 2.8 \times 2.8} \times \frac{\sqrt{3136}}{14} = ? \times 0.4$

1) Using $\frac{a^3 + b^3}{a^2 - ab + b^2} = a + b$ with $a = 7.2$ and $b = 2.8$, the first fraction simplifies to $7.2 + 2.8 = 10$. 2) $\sqrt{3136} = 56$. $\frac{56}{14} = 4$. 3) LHS $= 10 \times 4 = 40$. 4) $40 = ? \times 0.4 \implies ? = \frac{40}{0.4} = 100$.