Insert the corresponding expression:
(6×7×10)y+4+a= \left(6\times7\times10\right)^{y+4+a}= (6×7×10)y+4+a=
6y+4+a×7y+4+a×10y+4+a 6^{y+4+a}\times7^{y+4+a}\times10^{y+4+a} 6y+4+a×7y+4+a×10y+4+a