....帮忙

1.计算:2(a^3)^4+a^4*(a^4)^2=_3a^12_______

2.若x^3=-8a^6b^9,则x=_-2a^2b^3____

3.当a=1/4,b=4时,求代数式a^3(-b^3)^2+(-1/2ab^2)^3
a^3(-b^3)^2+(-1/2ab^2)^3
=(7/8)a^3b^6
=56

4.已知x=2,y=1/2,n为正整数.求x^3*3^(3n)*(y的n+1立方)^3
x^(3n)*3^3*(y的n+1立方)^3
=x^(3n)*3^3*y^(3n+3)
=2^(3n)*27*(1/2)^(3n)*(1/2)^3
=27/8

5.一列火车的速度时u(火)与一颗人造地球卫星的速度u(卫)之间的关系时u(卫)=u^3(火),已知火车的速度时7.5*10^4幂/小事,求人造地球卫星的速度.
v=(7.5*10^4)^3
=4.19875*10^7

6.观察下列等式:
(2+3)^2=2^2+2*2*3+3^2
(4+9)^2=4^2+2*4*9+9^2=2^4+2*2^2*3^2+3^4
(9+16)^2=9^2+2*9*16+16^2=(3^2)^2+2*3^2*4^2+(4^2)^2
根据以上规律,完成题目.
(1).(16+25)^2
=16^2+2*16*25+25^2=4^4+2*4^2*5^2+5^4
(2).100+2*10*12+144
=(10+12)^2=（根号10)^4+2*(根号10)^2(根号12)^2
+(根号12)^4
(3).(a^m+b^n)^2
=(根号a^m)^4+2*(根号a^m)^2(根号b^n)^2+(根号b^n)^4

3a^12
2a^2b^3
56