初二下册数学课本北师大版第85页习题3.5,

问题描述:

初二下册数学课本北师大版第85页习题3.5,

1 (1) (a+b)bc-(b+c)ac abc+b^2c-abc-ac^2 c( b^2-ac)--------------- = ------------------- = -------------ab^2c ab^2c ab^2c b^2-ac= -------ab^2(2) 3x-x(3-x) x^2= ------------ = --------(3-x)^2 9- x^22 ...