设函数f(x),g(x)满足f(x)+g(x)=3x^2-5x,2f(x)-g(x)=2x+3,求f(x)和g(x)

问题描述:

设函数f(x),g(x)满足f(x)+g(x)=3x^2-5x,2f(x)-g(x)=2x+3,求f(x)和g(x)

f(x)+g(x)=3x^2-5x,(1)
2f(x)-g(x)=2x+3 (2)
两式相加得3f(x)=3x^2-3x+3
则f(x)=x^2-x+1
(1)x2-(2)得
g(x)=2x^2-6x-1