解方程:(m²-mn-2n²)x²+(5m²+2mn-12n²)x+6m²+12mn=0
问题描述:
解方程:(m²-mn-2n²)x²+(5m²+2mn-12n²)x+6m²+12mn=0
其中m、n为常数,m²-mn-2n²≠0
我求你们了我要回答不要再来教育我了
答
十字相乘法.(m+n)(m-2n)x²+(5m²+2mn-12n²)x+2m(3m+6n)=0m+n 3m+6nm-2n 2m十字相乘,2m*(m+n)+(3m+6n)*(m-2n)=2m^2+2nm+3m^2-12n^2=5m^2+2mn-12n^2故方程分解为:[(m+n)x+(3m+6n)][(m-2n)x+2m]=0x1=-3(...