Question

数学题速度

1.x/x-1[(1+(x-1）/x]
2.1/x²-3x+2,1/5x-6-x²
最简公分母
3.x²-1/（x-2)(x-3)=A+B/X-2+C/x-3,求a，b，c

Answer 1

你好！

数学之美团为你解答

1、 x(x-1)
2、 1/(x²-3x+2) = 1/ [(x-1)(x-2)]
1/(5x - 6 - x²) = - 1/(x² - 5x+6) = - 1/[(x-2)(x-3)]
最简公分母 (x-1)(x-2)(x-3)
3、A +B/(x-2) +C/(x-3)
= [ A(x-2)(x-3) +B(x-3)+C(x-2) ] / [(x-2)(x-3)]
= [ Ax² +(B+C-5A)x - (6A+3B+2C)] / [(x-2)(x-3)]
与等式左边对比系数得
A=1
B+C-5A=0
6A+3B+2C=1
解得 A=1，B= -15，C=20

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Answer 2

1.x(x-1)
2.最简公分母 (x-1)(x-2)(x-3)
3.A=1，B= -15，C=20

Answer 3

待会让我算算