50×48%+(50-x)×62.5%+ 2/3x=100×56% x=?
2x+3x+4x+5x+x+6x+7x=100
(X+X)+(X-X)+(X*X)+(X/X)=100
x-1)(X-2)(x-3)...(x-50)+x(x-2)(X-3)...(X-50)+...+x(x-1)(x-2)
1X+2X+3X…+98X+99X+100X=50500X X等于多少?
1x+2x+3x+4x+5x+6x+7x…+99x=100
解方程:2x+4x+6x...+100x=1-(x+3x+5x+...+99x)
x^5+x^4 = (x^3-x)(x^2+x+1)+x^2+x
3x=x+100 x=50
3x(7-2x)+5x(2x-1)=4x(x-3)+56
x-2x+3x-4x+...+99x-100x=25
已知 X=4- 根号3 求 (X*X*X*X-6X*X*X-2X*X+18X+23) / (X*X-8X+15)的值
x/2*50+100=50x