Question

Answer 1

a) 2x-3 = 4x+1

<=>2x-4x = 3+1

<=> -2x = 4

<=> x = -2

Vậy....

b) x-3/5 + 1+2x/3 =6

<=> 3(x-3)/15 + 5(1+2x)/15 = 90/15

=> 3(x-3) + 5(1+2x) = 90

<=> 3x-9+5+10x=90
<=>13x=94

<=> x = 94/13

Vậy ....

c) x2 - 9 + (x-3)(x+1) = 0

<=> (x+3)(x-3)+(x-3)(x+1)=0

<=> (x-3)(x+3+x+1)=0

<=>(x-3)(2x+4)=0

<=>[x-3=0        <=>   x=3

      [2x+4=0               x=-2

 Vậy.....

d)3/x+1 + 4/2-x = 5x-11/x2-x-2

<=> 3/x+1 - 4/x-2 = 5x-11/(x+1)(x-2)

<=> 3(x-2)/(x+1)(x-2) - 4(x+1)/(x+1)(x-2) = 5x-11/(x+1)(x-2)

=> 3(x-2) -4(x+1) = 5x-11

<=> 3x-6-4x-4= 5x-11

<=> -6x = -1

<=> x = 1/6

Vậy...