4+5（2x-2.4)=4

x+2x+3x+4x+5x+6x+7x+8x+9x=9x-8x-7x-6x-5x-4x-3x-2x-x.x等于多少? (x-3/x-2)-(x-2/x-1)=(x-5/x4) -(x-4/x-3) x-2x+3x-4x+5x.+99x-100x=25求解 2x+3x+4x+5x+x+6x+7x=100 x(x+1)+(x+2)+(x+3)+(x+4)+(x+5) = 27求x *-----------------------------------------------*| 6 4 X | 8 X X | X X 5 || X X X | X X X | X 7 8 || X X X | X X X | X X X ||---------------+---------------+--------------- || X X X | X X X | 5 1 X || X X X | X 6 X | X X X || 8 X X | 3 5 X | 2 X X || x+2/x+1-x+4/x+3=x+6/x+5-x+8/x+7 x=? 写过程x(x-1)+2x(x+1)-3x(2x-5)-x(3x-2)+2x(2-x)=-5x(x-2)-4 5x-x=2.4 1.5x-x=1 6.6x-6x=1.8 2x-2/3x=3/4 解方程 解方程；x/x-4=5x/x-2 x-8/x-4=2-x-5/x-7 (X-5)(X+3)+(X-2)(X+4)=26 (4x+2)/x+(4x-22)/(x-5)=(x-6)/(x-4)+(7x+9)/(x+1) 1+x+x^2+x^3+x^4+x^5+x^6+x^7+x^8+x^9+x^10+x^11+x^12=97.8x+x^2+x^3+x^4+x^5+x^6+x^7+x^8+x^9+x^10+x^11+x^12=97.8 好多年没有用过过数学公式了 想不起来怎么算了 想知道 X值是多少 (x-5)/(x/7)+(x-2)/(x-4)=(x-3)/(x-5)+(x-4)/(x-6) (x+2)/(x+1)-(x+3)/(x+2)=(x+4)/(x+3)-(x+5)/(x+4) x-1/x-2-x-3/x-4=x-2/x-3-x-4/x-5怎么做? (x-3)/(x-2)-(x-2)/(x-1)=(x-5)/(x-4)-(x-4)/(x-3) 帮个忙呗~~~