2道数学计算(1) :(a^2-a)^2-(a-1)^2(2) :已知x-y = -1,xy=3.求x^3y-2x^2y^2+xy^3的值第(2)个问题不要算!下面是同一题:改成:计算填空:3^3-4*3^2+10*3=3^4-4*3^3+10*3^2=3^5-4*3^4+10*3^3=猜想下列个题的结果并验证:1.3^2004-4*3^2003+10*3^2002=2.3^n+2-4*3^n+1+10*3^n=
2019-05-23
2道数学计算
(1) :(a^2-a)^2-(a-1)^2
(2) :已知x-y = -1,xy=3.求x^3y-2x^2y^2+xy^3的值
第(2)个问题不要算!下面是同一题:
改成:计算填空:
3^3-4*3^2+10*3=___
3^4-4*3^3+10*3^2=___
3^5-4*3^4+10*3^3=___
猜想下列个题的结果并验证:
1.3^2004-4*3^2003+10*3^2002=_____
2.3^n+2-4*3^n+1+10*3^n=_____
优质解答
(1) (a^2-a)^2-(a-1)^2
=a^2(a-1)^2-(a-1)^2
=(a-1)^2(a^2-1)
=(a+1)(a-1)^3
(2)x^3y-2x^2y^2+xy^3
=x^2y(x-y)-xy^2(x-y)
=xy(x-y)(x-y)
=xy(x-y)^2
=3*(-1)^2
=3
3^3-4*3^2+10*3=3*7_=21__
3^4-4*3^3+10*3^2=_3^2*7=63__
3^5-4*3^4+10*3^3=_3^3*7=189__
猜想下列个题的结果并验证:
1.3^2004-4*3^2003+10*3^2002=_3^2002*7____
2.3^n+2-4*3^n+1+10*3^n=_3^n*7____
(1) (a^2-a)^2-(a-1)^2
=a^2(a-1)^2-(a-1)^2
=(a-1)^2(a^2-1)
=(a+1)(a-1)^3
(2)x^3y-2x^2y^2+xy^3
=x^2y(x-y)-xy^2(x-y)
=xy(x-y)(x-y)
=xy(x-y)^2
=3*(-1)^2
=3
3^3-4*3^2+10*3=3*7_=21__
3^4-4*3^3+10*3^2=_3^2*7=63__
3^5-4*3^4+10*3^3=_3^3*7=189__
猜想下列个题的结果并验证:
1.3^2004-4*3^2003+10*3^2002=_3^2002*7____
2.3^n+2-4*3^n+1+10*3^n=_3^n*7____