先化简再求值:5m²n-1/2(8mn+2n²)+4(m²n+mn-2n²).其中m=-3,n=2

先化简再求值:5m²n-1/2(8mn+2n²)+4(m²n+mn-2n²).其中m=-3,n=2
先化简再求值:5m²n-1/2(8mn+2n²)+4(m²n+mn-2n²).其中m=-3,n=2

先化简再求值:5m²n-1/2(8mn+2n²)+4(m²n+mn-2n²).其中m=-3,n=2
5m²n-1/2(8mn+2n²)+4(m²n+mn-2n²)
=5m²n-4mn-n²+4m²n+4mn-8n²
=9m²n-9n²
当m=-3,n=2时
原式=162-36=126