已知(x减2)乘(x加5)分之4x加1等于x加五分之a加x减2分之b,求ab
问题描述:
已知(x减2)乘(x加5)分之4x加1等于x加五分之a加x减2分之b,求ab
答
(x减2)乘(x加5)分之4x加1等于x加五分之a加x减2分之b(4x+1)/(x-2)(x+5)=a/(x+5)+b/(x-2)(4x+1)/(x-2)(x+5)=(ax-2a+bx+5b)/(x-2)(x+5)(4x+1)/(x-2)(x+5)=[(a+b)x+(-2a+5b)]/(x-2)(x+5)∴a+b=4 -2a+5b=1∴a=19/7 ...