用直式计算下列各式1.(x+2y+3z)-(3x+2y-z)+(2x-3y+4z)2.(2x^3+4x+7)+(8x^3-6-4x^2)-(-5x^3+7-6x-5x^2)3.(x^2-xy+y^2)(x+y)4.(1+2x^2-3x-4x^3)(4-7x+2x^2)5.(t^5+t^4+t^3+t^2+t+1)(t-1)6.(x^3-3x+2)÷(x+2)7.(1-5x+5x^2-4x^3)÷(x^2-x+1)8.(x^3+y^3)÷(x+y)用

Question

用直式计算下列各式
1.(x+2y+3z)-(3x+2y-z)+(2x-3y+4z)
2.(2x^3+4x+7)+(8x^3-6-4x^2)-(-5x^3+7-6x-5x^2)
3.(x^2-xy+y^2)(x+y)
4.(1+2x^2-3x-4x^3)(4-7x+2x^2)
5.(t^5+t^4+t^3+t^2+t+1)(t-1)
6.(x^3-3x+2)÷(x+2)
7.(1-5x+5x^2-4x^3)÷(x^2-x+1)
8.(x^3+y^3)÷(x+y)
用分数系数法计算下列各式
1.2x^2-1-(x^2-x+3)-(x^2+x-4)
2.2x+5y+10+(4x-3y-7)-(3x-4y+8)
3.(x^2+xy+y^2)(x-y)
4.(a^2-a+1)(a^2+a+1)
5.(4x^3+2-3x)(2x^2-3+x^3)
6.(x^2+5x+6) ÷(x+2)
7.(35x^3+57x^2+13x+1)÷(5x+1)
8.(2x^4-4x^3-3x^2-x+1)÷(x^2-3x+1)
将下列二次函数配方成y=a(x-h)+k的形式,指出顶点坐标对称轴方程和函数最大或最小值
1.y=X^2-4x
2.y=1+8x-X^2
3.y=3X^2+9x+6
4.y=-2x^2+4x-12
5.y=2分之一x^2+x-2
6.y=-3分之一x^2+3分之一x-6

Answer 1

用直式计算下列各式
1.(x+2y+3z)-(3x+2y-z)+(2x-3y+4z)=-3y+8z
2.(2x^3+4x+7)+(8x^3-6-4x^2)-(-5x^3+7-6x-5x^2)=15x^3+x^2-2x-6
3.(x^2-xy+y^2)(x+y)=x^3+y^3
4.(1+2x^2-3x-4x^3)(4-7x+2x^2)=
5.(t^5+t^4+t^3+t^2+t+1)(t-1)=(1-t^6)/(1-t) *（t-1）=t^6-1
6.(x^3-3x+2)÷(x+2)=x^2(x+2)-2x(x+2)+（x+2） /（x+2）=（x-1）^2
7.(1-5x+5x^2-4x^3)÷(x^2-x+1)=-4x+1
8.(x^3+y^3)÷(x+y)=x^2-xy+y^2
用分数系数法计算下列各式
1.2x^2-1-(x^2-x+3)-(x^2+x-4)=0
2.2x+5y+10+(4x-3y-7)-(3x-4y+8)=3x+6y-5
3.(x^2+xy+y^2)(x-y)=x^3-y^3
4.(a^2-a+1)(a^2+a+1)=(a^2+1)^2-a^2=a^4+a^2+1
5.(4x^3+2-3x)(2x^2-3+x^3)=
6.(x^2+5x+6) ÷(x+2)=x+3
7.(35x^3+57x^2+13x+1)÷(5x+1)=7x^2+10x+1-2x/(5x+1)
8.(2x^4-4x^3-3x^2-x+1)÷(x^2-3x+1)=2x^2+2x+5-(4-12x)/(x^2-3x+1)
将下列二次函数配方成y=a(x-h)+k的形式,指出顶点坐标对称轴方程和函数最大或最小值
1.y=X^2-4x
y=(x-2)^2-4,则顶点坐标为（2,-4）对称轴方程为x=2,有最小值y=-4
2.y=1+8x-X^2
y=-（x-4)^2+17,则顶点坐标为（4,17）对称轴方程为x=4,有最大值y=17
3.y=3X^2+9x+6
y=3（x-3/2)^2-0.75,则顶点坐标为（1.5,-0.75）对称轴方程为x=1.5,有最小值y=-0.75
4.y=-2x^2+4x-12
y=-2(x-1)^2-10,则顶点坐标为（1,-10）对称轴方程为x=1,有最大值y=-10
5.y=2分之一x^2+x-2
y=0.5(x+1)^2-2.5,则顶点坐标为（-1,-2.5）对称轴方程为x=-1,有最小值y=-2.5
6.y=-3分之一x^2+3分之一x-6
y=1/3 (x-0.5)^2-73/12,则顶点坐标为（0.5,-73/12）对称轴方程为x=0.5,有最小值y=-73/12