(x+7):6=7:2.1

x/x-2+x-9/x-7=x+1/x-1+x-8/x-6, x/x-2+x-9/x-7=x+1/x-1+x-8/x-6, x+2x+3x+4x+5x+6x+7x+8x+9x=9x-8x-7x-6x-5x-4x-3x-2x-x.x等于多少? 1.(x*2-3x+3)/(x*2-3x+2)-(x*2-5x+7)/(x*2-5x+6)-1/(x*2-4x+3)2.1/x(x+1)+2/(x+1)(x+3)+3/(x+3)(x+6) 3.已知：x*2-3x+1=0,求x*2+1/x*2. 2x+3x+4x+5x+x+6x+7x=100 (x+7/x+6) +(x+9/x+8)=9x=(x+10/x+9) +(x+6/x+5) x+2/x+1-x+4/x+3=x+6/x+5-x+8/x+7 x=? x-4/x-5 - x-5/x-6=x-7/x-8 - x-8/x-9求x=? 已知3x*x-x=1,求6x*x*x+7x*x-5x+2000 (x+8)(x+6)(x+7)+(x+5)(x+6)(x+7)=(x+5)(x+8)(x+7)+(x+5)(x+8)(x+6) 4.2-0.6x=3.6x 5x+2x=33.6 7x-4x=0.75 2x+7x+2.1=12 56x-32x-119=361 x+5=2x 3x+9=6x 4x-28=2x 2x+18=7x 5x=25*4-15x 7x-x+2*3=29.4 (28.8+5.5x+3.2）除2=71 *-----------------------------------------------*| 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 || 27046=2x( )+7x( )+4x( )+6x( ) 47026=4x()+7x()+2x()+6x() 2706=2x( )+7x( )+4x( )+6x( ) (x+7)(x+6)-(x-2)(x+1)=? x+5/7x=6 x x等于多少 0.3+0.3x=0.39 x= 2x-1.5x=7.6x x= 0.36x÷0.3=1.2 x=6（x+1.2)=18.6 x= 7x+2x = 8.1 x= (x-5）÷3=1.7 x=5（x+1.1)=15.5 x= 9x+25=70 x= 7x-4x=2.1 x=