1/x-3+2=5/x-1+x
đk : x k = 1,3
<->x-1+2(x-1)(x-3)=5(x-3)+x(x-1)(x+3)
<->x-1+2(x mũ 2-4x+3)=5x-15+x(x mũ 2 -4x +3)
<->2x mũ 2-5x+5=5x-15+x mũ 3 -4x mũ 2+ 3x
<-> x mũ 3-6x mũ 2+13x-20=0
<-> x mũ 3- 4x mũ 2- 2x mũ 2-8x+5x-20=0
<-> x mũ 2(x-4)-2x(x-4)+5(x-4)=0
<-> (x-4)-( x mux 2 -2x+5)=0
<->x-4=0
vif x mux 2 -2x+5=(x+1) mux 2+4>0
<-> x=4(t/m)
chi tiet lm roi bn nha