解:原式可化为3(x²+4x+4)+(4x²-4X+1)-7(x²-9)=283x²+12x+12+4x²-4x+1-7x²+63-28=08x+48=08x=-48解得x=-6望采纳,谢谢祝学习天天向上,不懂可以继续问我
3(x+2)²+(2x-1)²-7(x+3)(x-3)=283(x²+4x+4)+(4x²-4x+1)-7(x²-9)-28=08x+48=08x=-48x=-6