Question

Aratati ca ecuatiile urmatoare au solutia -2 ;

2x + 4 = 0

-1 + 3x = 4x + 1

5x - 3 = x - 11

10(x - 3 ) + 2 = 4( 8x + 4 )

2,5x + 2 = 3( 1,5x + 2 )

Answer 1

2x + 4 = 0 
2x=-4
x=-2

-1 + 3x = 4x + 1 
3x-4x=1+1
-x=2  /(-1)
x=-2

5x - 3 = x - 11 
5x-x=-11+3
4x=-8
x=-2

10(x - 3 ) + 2 = 4( 8x + 4 ) 
10x-30+2=32x+16
32x-10x=-28-16
22x=-44
x=-2

2,5x + 2 = 3( 1,5x + 2 )
2,5x+2=4,5x+6
4,5x-2,5x=-6+2
2x=-4
x=-2