Explanation:

In this question as we need to find the power of base 2 given in R.H.S,
it's clear that factors other than 2 will be cancelled out on calculation in L.H.S.
Therefore, we can solve this question just by picking 2 is as bases with their powers in L.H.S.

⇒ 2^{3.5 + 3.5} = 2^x 
⇒ 2⁷ = 2^x ⇒ x = 7.