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解方程5/(x-1)(x+2)+3/(x+2)(x+3)=2/(x-1)(x+3)不要乘(x-1)(x+2)(x+3)这个公分母,应该还有更简便的方法.

题目详情
解方程5/(x-1)(x+2)+3/(x+2)(x+3)=2/(x-1)(x+3)
不要乘(x-1)(x+2)(x+3)这个公分母,应该还有更简便的方法.
▼优质解答
答案和解析
5/(x-1)(x+2) + 3/(x+2)(x+3) = 2/(x-1)(x+3)
3/(x-1)(x+2) + 2/(x-1)(x+2) + 3/(x+2)(x+3) = 2/(x-1)(x+3)
3/(x-1)(x+2) + 3/(x+2)(x+3) = 2/(x-1)(x+3) - 2/(x-1)(x+2)
3 {1/(x-1)(x+2) + 1/(x+2)(x+3) } = 2 { 1/(x-1)(x+3) - 1/(x-1)(x+2) }
3 {(x+3)+(x-1)} / { (x-1)(x+2)(x+3) } = 2 { (x+2)-(x+3) } / { (x-1)(x+3) (x+2) }
3 ( 2x+2 ) / { (x-1)(x+2)(x+3) } = 2 { - 1 } / { (x-1)(x+3) (x+2) }
6 ( x+1 ) / { (x-1)(x+2)(x+3) } = -2 / { (x-1)(x+3) (x+2) }
3 ( x+1 ) / { (x-1)(x+2)(x+3) } = -1 / { (x-1)(x+3) (x+2) }
{3 x+3+1 } / { (x-1)(x+2)(x+3) } = 0
{3 x+4 } / { (x-1)(x+2)(x+3) } = 0
3 x+4 = 0
x=-4/3