Question

Giúp tớ bài 2 với

Answer 1

2:

a)x / 2x+2 + x / 3x-3 + -x / 1-x²

= x / 2(x+1) + x / 3(x-1) + x / x²-1

= x(x-1) / 2(x+1)(x-1) + x(x+1) / 3(x-1)(x+1) + x / (x-1)(x+1)

= 3x(x-1) / 6(x+1)(x-1) + 2x(x+1) / 6(x+1)(x-1) + 6x / 6(x+1)(x-1)

= 3x(x-1) + 2x(x+1) + 6x / 6(x+1)(x-1)

= 3(x²-x) + 2(x²+x) + 6x / 6(x+1)(x-1)

= 3x² - 3x + 2x² + 2x + 6x / 6(x+1)(x-1)

= 5x² + 5x / 6(x+1)(x-1)

= 5x(x+1) / 6(x+1)(x-1)

= 5x / 6(x-1) = 5(x-1) + 5 / 6(x-1)

= 5(x-1) / 6(x-1) + 5 / 6(x-1)

= 5/6 + 5 / 6(x-1)

b)x²-5x / x³+1 + x+2 / x²-x+1 + 1 / x+1

= x²-5x / x³+1 + (x+2)(x+1)+x²-x+1 / (x²-x+1)(x+1)

= x²-5x / x³+1 + x²+3x+2+x²-x+1 / x³+1

= x²-5x+x²+3x+2+x²-x+1 / x³+1

= 3x²-3x+3 / (x²-x+1)(x+1)

= 3(x²-x+1) / (x²-x+1)(x+1) = 3 / x+1