①下列计算正确的是( )A (-3x)^2=-9x^2 B.(-3x)^2=9x^2 C.(-3)^2= -6x^2 D(-3x)^2=6x^2

问题描述:

①下列计算正确的是( )A (-3x)^2=-9x^2 B.(-3x)^2=9x^2 C.(-3)^2= -6x^2 D(-3x)^2=6x^2
②计算a(-2a)^3 · (a^2)^5的结果是( )(要化简)
③如果(x^3y^n)^2=x^6 y^8,则n等于( ).
④已知2^x=a.2^y=b.求(2^x+y)+(2^3x+2y)的值
⑤已知x^n=2.y^n=3,求(x^2y)^2n 的值

①下列计算正确的是(B)A (-3x)^2=-9x^2 B.(-3x)^2=9x^2 C.(-3)^2= -6x^2 D(-3x)^2=6x^2②计算a(-2a)^3 · (a^2)^5的结果是(8a^14)(要化简)③如果(x^3y^n)^2=x^6 y^8,则n等于( 4 ).④已知2^x=a.2^y=b.求...第④题log哪冒出来的。第⑤题请化简2^x=a.log(2,2^x)=log(2,a)=x2^y=b. log(2,2^y)=log(2,b)=y