初一数学一课一练七年级数学一课一练中第95页第一题(x+2)/1+(x+7)/1=(x+3)/1+(x+6)/1第二题(x+2)/(x+3)+(x+3)/(x+4)=(x+4)/(x+5)=(x+1)/(x+2)不是两等号,第二题(x+2)/(x+3)+(x+3)/(x+4)=(x+4)/(x+5)+(x+1)

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初一数学一课一练七年级数学一课一练中第95页第一题(x+2)/1+(x+7)/1=(x+3)/1+(x+6)/1第二题(x+2)/(x+3)+(x+3)/(x+4)=(x+4)/(x+5)=(x+1)/(x+2)不是两等号,第二题(x+2)/(x+3)+(x+3)/(x+4)=(x+4)/(x+5)+(x+1)
初一数学一课一练
七年级数学一课一练中第95页
第一题(x+2)/1+(x+7)/1=(x+3)/1+(x+6)/1
第二题(x+2)/(x+3)+(x+3)/(x+4)=(x+4)/(x+5)=(x+1)/(x+2)
不是两等号,第二题(x+2)/(x+3)+(x+3)/(x+4)=(x+4)/(x+5)+(x+1)/(x+2)

初一数学一课一练七年级数学一课一练中第95页第一题(x+2)/1+(x+7)/1=(x+3)/1+(x+6)/1第二题(x+2)/(x+3)+(x+3)/(x+4)=(x+4)/(x+5)=(x+1)/(x+2)不是两等号,第二题(x+2)/(x+3)+(x+3)/(x+4)=(x+4)/(x+5)+(x+1)
第一题(x+2)/1+(x+7)/1=(x+3)/1+(x+6)/1
(x+2)(x+7)/(x+7)+(x+7)(x+2)/(x+2)=(x+3)(x+6)/(x+6)+(x+6)(x+3)/(x+3)
(x+2)(x+7)/(2x+9)=(x+3)(x+6)/(2x+9)
当2x+9=0时,有x=-2/9
当2x+9≠0时,有
(x+2)(x+7)=(x+3)(x+6)
x^2+9x+14=x^2+9x+18
无解
所以x=-2/9
(x+2)/(x+3)+(x+3)/(x+4)=(x+4)/(x+5)+(x+1)/(x+2)
(x+2)/(x+3)-(x+1)/(x+2)=(x+4)/(x+5)-(x+3)/(x+4)
(x+2)(x+1)/(x+1)(x+3)-(x+2)(x+1)/(x+2)(x+2)=(x+4)(x+3)/(x+5)(x+3)-(x+4)(x+3)/(x+4)(x+4)
(x+2)(x+1)/[(x^2+4x+3)-(x^2+4x+4)]=(x+4)(x+3)/[(x^2+8x+15)-(x^2+8x+16)]
(x+2)(x+1)/(-1)=(x+4)(x+3)/(-1)
(x+2)(x+1)=(x+4)(x+3)
x^2+3x+2=x^2+7x+12
4x=-10
x=-2/5