Question

若代数式（2x^2+3ax-y)-2(bx^2-3x+2y-1)的值与字母x的取值无关,则代数式（a-b)-(a+b)的

Answer 1

(2x^2+3ax-y)-2(bx^2-3x+2y-1)

=2x²+3ax-y-2bx²+6x-4y+2

=(2-2b)x²+(3a+6)x-5y+2

与字母x的取值无关

则2-2b=0,3a+6=0

则b=1,a=-2

（a-b)-(a+b)=-2