若(A/x-5)+(B/x+2)=5x-4/x2-3x-10试求A,B的值
热心网友
猜想：A/(x-5)+B/(x+2)=(5x-4)/(x^2-3x-10)---A/(x-5)+B/(x+2)=(5x-4)/[(x-5)(x+2)]---A(x+2)+B(x-5)=5x-4---(A+B)x+(2A-5B)=5x-4比较系数得到方程组：A+B=5;2A-5B=-4.解之得A=3;B=2.
热心网友
两边同乘x^2-3x-10(x+2)A+(x-5)B=5x-4(A+B)x+(2A-5B)=5x-4A+B=5;2A-5B=-4.解得A=3,B=2