已知2x+6/(x-2)(x-3)=A/x-2++B/x-3+求4A-B
1个回答
关注
展开全部
4A-B=8
咨询记录 · 回答于2022-12-18
已知2x+6/(x-2)(x-3)=A/x-2++B/x-3+求4A-B
4A-B=8
因为(2x+6)/(x-2)(x-3)=A/(x-2)+B/(x-3)=(A(x+3)+B(x-2))/(x-2)(x+3)=(Ax+3A+Bx-2B)/(x-2)(x+3)所以A+B=23A-2B=6解得A=2B=0所以4A-B=4×2-0=8
因为(2x+6)/(x-2)(x-3)=A/(x-2)+B/(x-3)=(A(x+3)+B(x-2))/(x-2)(x+3)=(Ax+3A+Bx-2B)/(x-2)(x+3)所以A+B=23A-2B=6解得A=2B=0所以4A-B=4×2-0=8