(6x²y³)*(1/12 x²y)(4x²y⁴)= 2x⁶y⁸
(3x³y⁵)(1/15xy)= x⁴y⁶/5
(1/3x²y)³= x⁶y³/27
b6=b1*q^5
b6=-81*(-1/3)^5=-81*(-1/243)=1/3