x+4=x+2 2x-9+12 10x+7x-3=4x+1 4-3(x+3)=(-8)

x+4=x+2 x-x=2-4 0=-2 2x-9+12 2x= 3 / :2 x=1,5 10x+7x-3=4x+1 17x-3=4x=1 17x-4x=1+4 13x=5 / :13 x=5/13 4-3(x+3)=(-8) 4-3x-9=-8 -3x=-8-4+9 -3x=-3 / :(-3) x=1