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解方程:x/(x%2)+(x%9)/(x%7)=(x+1)/(x%1)+(x%8)/(...

解: x/(x-2)+(x-9)/(x-7)=(x+1)/(x-1)+(x-8)/(x-6) 因为x/x-2=(x-2+2)/x-2=1+2/x-2.其他类似。 即 1+2/(x-2)+1-2/(x-7)=1+2/(x-1)+1-2/(x-6) 1/(x-2)-1/(x-7)=1/(x-1)-1/(x-6) 可得-5/(x-2)(x-7)=-5/(x-1)(x-6) (x-2)(x-7)=(x-1)(x-6) 化简...

x=16

解答如下:

解:1、x-x/7-7-1/x=2,6x/7-1/x=9,6x²-7=63x 得:x=(63-√4137)/12或x=(63+√4137)/12 2、x/(x-7)-1/(7-x)=2,x+1=2*(x-7),x=15 3、x/(x-7)-7-1/x=2,x/(x-7)-1/x=9,x²-(x-7)=9(x²-7x),8x²-62x-7=0 x=(62-√4068)/16或x=(...

①(x+1.7)×2=9.2, (x+1.7)×2÷2=9.2÷2, x+1.7=4.6, x+1.7-1.7=4.6-1.7, x=2.9;②8x-4x=0.64,x(8-4)=0.64, 4x=0.64, 4x÷4=0.64÷4, x=0.16;③2x-0.24=0.12,2x-0.24+0.24=0.12+0.24, 2x=0.36, 2x÷2=0.36÷2, x=0.18;④7x+2.5X=3.8...

把方程左边第一个因式与第四个因式相乘,第二个因式与第三个因式相乘,得(x2+5x-14)(x2+5x+4)=19.设y=(x2+5x?14)+ (x2+5x+4) 2=x2+5x-5,①则(y-9)(y+9)=19,即y2-81=19.解得y1.2=±10,将y1、y2的值代入①式得,x1.2=?5±852,x3.4=?5±52,

[(x+1)/(x+2)]-[1/(x+7)]=[(x+2)/(x+3)]-[1/(x+6)] 为简化起见,特设:(x+1)=a,(x+2)=b,(x+3)=c,(x+6)=d,(x+7)=e 于是公式成为:a/b-1/e=b/c-1/d 先移项:a/b-b/c=1/e-1/d 等式两边同乘以:bcde,也就是同乘(x+2)(x+3)(x+6)(x+7) 得:de(ac-bb)=bc(d-e)...

:(x+3)/(x+2)-(x+5)/(x+4)=(x+7)/(x+6)-(x+9)/(x+8) 1+1/(x+2)-1-1/(x+4)=1+1/(x+6)-1-1/(x+8) 1/(x+2)-1/(x+4)=1/(x+6)-1/(x+8) 2/(x+2)(x+4)=2/(x+6)(x+8) 2(x+2)(x+4)=2(x+6)(x+8) (x+6)(x+8)=(x+2)(x+4) x^2+14x+48=x^2+6x+8 8x=-40 x=-5

孩子是这么做的: 2(X+1.7)=9.2 左边去括号 2X+2*1.7=9.2 移项 2X=9.2-2*1.7 即2X=9.2-3.4 2X=5.8 X=2.9

(1)去括号得:x-2x+2=3-2x移项、合并同类项得:x=1;(2)去分母得:3(x+5)-6=2(x+7)去括号得:3x+15-6=2x+14移项、合并同类项得:x=5.

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