Question

Answer 1

a) 7 + (x - 2) = 3(x - 1)

<=> 7 + x - 2 = 3x - 3

<=> x - 3x = -3 - 7 + 2

<=> -2x = -8

<=> x = 4

b) (x - 1) - (2x - 1) = 9 - x

<=> x - 2x + x = 9 + 1 - 1

<=> 0x = 9 (vô lí)

--> vô nghiệm

Answer 2

a: =>x+5-3x+3=0

=>-2x=-8

hay x=4

b: =>x-1-2x+1-9+x=0

=>-9=0(vô lý)