Question

giai pt này giùm mik đê:\(\dfrac{2x-5}{x-2}-\dfrac{3x-5}{x-1}=-1\)

Answer 1

ĐKXĐ: x\(\ne2\), \(x\ne1\)

\(\dfrac{2x-5}{x-2}-\dfrac{3x-5}{x-1}=-1\)

<=> \(\dfrac{\left(2x-5\right)\left(x-1\right)}{\left(x-1\right)\left(x-2\right)}-\dfrac{\left(3x-5\right)\left(x-2\right)}{\left(x-1\right)\left(x-2\right)}=\dfrac{-1.\left(x-1\right)\left(x-2\right)}{\left(x-1\right)\left(x-2\right)}\)

=> 2x²-2x-5x+5-3x²+6x+5x-10= -x²+2x-2+x

<=> 2x²-2x-5x+5-3x²+6x+5x-10+x²-2x+2-x=0

<=> x-3=0

<=> x=3 (thỏa mãn ĐKXĐ)

Vậy S=\(\left\{3\right\}\)