We can rewrite the equation as 2ᵃ⁻³ = 64¹². To solve for 'a', we need to express both sides of the equation with the same base. The base on the left side is 2. We can express 64 as a power of 2. 64 = 2 × 2 × 2 × 2 × 2 × 2 = 2⁶.