{2m(x平方)-(x平方)+3x+1}-{5(x平方)-4(y平方)+3x}化简后不含(x平方)项 求多项式 2(m立方)-[(3立方)-(4m-5)+m]的值
{2m(x平方)-(x平方)+3x+1}-{5(x平方)-4(y平方)+3x}化简后不含(x平方)项 求多项式 2(m立方)-[(3立方)-(4m-5)+m]的值
解:{2m(x平方)-(x平方)+3x+1}-{5(x平方)-4(y平方)+3x}
=2m(x平方)-(x平方)+3x+1-5(x平方)+4(y平方)-3x
=(2m-1-5)(x平方)+4(y平方)+1
∵{2m(x平方)-(x平方)+3x+1}-{5(x平方)-4(y平方)+3x}化简后不含(x平方)项
∴2m-1-5=0,解得m=3
∴2(m立方)-[(3立方)-(4m-5)+m]
=2X(3的立方)-(3立方)+(4X3-5)-3
=(3的立方)+7-3
=27+4
=31