分解因式:①a²+2a(b+c)+(c+b)²②m²x²+2m²xy+m²y²③(2x-3y)(m+n)+(3x-2y)(m+n)④6x(x+y)³+3(y-x)³计算(-3a³)²·a³+(-4a)²·a^7-(3a³)³

问题描述:

分解因式:①a²+2a(b+c)+(c+b)²②m²x²+2m²xy+m²y²
③(2x-3y)(m+n)+(3x-2y)(m+n)④6x(x+y)³+3(y-x)³
计算(-3a³)²·a³+(-4a)²·a^7-(3a³)³