2.5:5=1/2:X

3道简单的分式方程,1.3/(1-x^) = 2/(1+2x+x) - 5/1-2x+x^2.5x/(x^+x-6) + (2x-5)/(x^-x-12) = (7x-10)/(x^-6x+8)3.(x+1)/(x+2) + (x+6)/(x+7) = (x+2)/(x+3) + (x+5)/(x+6) 解方程x/(x-2)=2x/(x-3)+(1-x)/(x-5x+6) x(x-2)-2x(x+1)-3x(x-5) 其中x=负½ (x-3/x-2)-(x-2/x-1)=(x-5/x4) -(x-4/x-3) x(x+1)+(x+2)+(x+3)+(x+4)+(x+5) = 27求x f(x,-x)=x^2+2x,fx(x,-x)=5x+1,则fy(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 *-----------------------------------------------*| 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 || (1) 2.5+3X=1.1 (2) 12X-5X=2.1 (3) X-0.3X=1.4 X=1.1 X=2.1 X=1.4 X=?X=0.3 X=? 求这三道题的值域f(x)=x^2+4x+5 x∈{2.5} f(x)=x^2-4x+5 x∈{1.5} f(x)=x+√1-x 解方程3x=x+4,2.6x-8=2.4x,4x+12=10x+3 ,7x=12-×,2.5x=2x+4,5x+3=6x+1,详列计算, 2x(x-1)-x(2x-5)=15 5/x^2+x - 1/x^2-x=0 X-5+8*X=7*X-2*X-1 填九宫格帮帮忙.x x 6 x x 7 x x 98 x x x 3 x 1 x x 9 x x 6 x 5 x 3 x x x 3 x x x x 1 8x x x 9 x 1 x x x2 1 x x x x 6 x x x 6 x 7 x 3 x x 1 x x 9 x 2 x x x 47 x x 8 x x 5 x x 请问,这十道关于一元一次方程的题目我做对了吗?（1）2X+3X+4X=189X=18X=2(2)13X-15X+X=-3-1X=-3X=3(3)2.5X+10X-6X=15-21.56.5X=6.5X=1(4)4X+3(2X-3))=12-（X+4）4X+6X-9=12X-4810X-12X=-48+9-2X=-57X=28.5(5) 7X+2(3X-3)=207X+6X-6=2013X=20+6 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