原式=[-4/3×(2a-b)²]³×[-1/2×(2a-b)^5]²
=(-4/3)³×(2a-b)^(2×3)×(-1/2)²×(2a-b)^(5×2)
=-64/27×(2a-b)^6×1/4×(2a-b)^10
=-64/27×1/4×(2a-b)^6×(2a-b)^10
=-16/27×(2a-b)^(6+10)
=(-16/27)(2a-b)^16