(1)已知x^m=3,x^n=6,求x^m-n,x^3m-2n的值 (2)已知x^4n+3/x^n+1=x^n+3*x^n+5,求n的值
问题描述:
(1)已知x^m=3,x^n=6,求x^m-n,x^3m-2n的值 (2)已知x^4n+3/x^n+1=x^n+3*x^n+5,求n的值
答
(1)已知x^m=3,x^n=6,求x^m-n,x^3m-2n的值
x^m-n=x^m/x^n =3/6=0.5
x^3m-2n=(x^m)^3/(x^n)^2=3^3/6^2=27/36=3/4