0.3X+0.6*(20-X)=9,求X

0.3X+0.6*(20-X)=9,求X X+0.3X=1000 求X? (x^2-3x+1) (x^2+3x+2)( x^2-9x+20)= -30求X 解方程X-0.6X=20求x解 (16x-13)/(4x-3)-(20x-24)/(4x-5)=(32x-30)/(8x-7)-(40x-43)/(8x-9)求x x-4/x-5 - x-5/x-6=x-7/x-8 - x-8/x-9求x=? 16^X - 12^X -9^X = 0.求X. 16^x+12^x=9x 求x! 4x-5=25-9x+x 求x? 4x-3x(20-x)=4求x 已知x=1/x,求x^2-6x+9/x-3/x+3/x^2+6x+9 求方程解x-5/x-4+x-9/x-8=x-8/x-7+x-6/x-5 x-4／x-5-x-5／x-6=x-7／x-8-x-8／x-9求大神帮助 (x-2)(x*x-6x-9)=x(x-5)(x-3),求6x的算术平方根 已知x=2π+1求 |x-1|+|x-2|+|x-3|+|x-4|+|x-5|+|x-6|+|x-7|+|x-8|+|x-9|+|x-10| 已知x=2π+1.求(X-1)+(X-2)+(X-3)+(X-4)+(X-5)+(X-6)+(X-7)+(X-8)+(X-9)+(X-10) 求(6x+5)(6x-5)-(4x+3)(9x-5)=-20 f(x) = (2 x + 5)/(x^2 + 9 x + 20) 求定义域?