x取任何有理数时,总有2ax^2-b/3x+2=-4x^2-x+2,则a+b的值是( )A.-2 B .1C .0D .-1
问题描述:
x取任何有理数时,总有2ax^2-b/3x+2=-4x^2-x+2,则a+b的值是( )A.-2 B .1C .0D .-1
答
x取任何有理数时,总有2ax^2-b/3x+2=-4x^2-x+2
x任何次方的对应系数相等,即
2a=-4
-b/3=-1
解得a=-2
b=3
所以a+b=-2+3=1
选B