2.9x-0.9×7=2x+2.1

2.9x-0.9×7=2x+2.1 9x-0.9乘7=2x+2.1 x=?9x-0.9乘7=2x+2.1 x=?还有：3(2x-1.2)=2(x+3.5) x=?2.4x-9.8=1.4x-9 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. 帮个忙 解个方程15X+5=8X+40 15x+5=8x+40 9x-0.9*7=2x+2.1 3x-0.2*10=2x 96+6x=90+8x 0.5x+30-0.3x=420 4x-2=9x-6 (x+12)(x-2)+(x+7)(x+8)-(x+5)(x-10),其中x=2 2x+3x+4x+5x+x+6x+7x=100 x+2/x+1-x+4/x+3=x+6/x+5-x+8/x+7 x=? (x+1)/(x+2)+(x+8)/(x+9)解答x+1/x+2+x+8/x+9=x+2/x+3+x+7/x+8 5x+2x=33.6,7x-4x=0.75,2x+7x+2.1=12,56x-32x-119=361,解方程 *-----------------------------------------------*| 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 || 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 1.解方程：2x-1分之x-1 + 1-2x分之5x-8= - 3 2.1-x分之3-x - 7-x分之5-x =1 - x²-8x+7分之x²-2 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 7x^2-5x=2x^2+x x-2/3x+x+2/7x=30