3x-1=2(x-2) 3(x+5)=x-3 19(y+9)=3(x-8)
а в третьем точно y?
3x-1=2x-43x-2x=-4+1x=-3----------3x+15=7-5x3x+5x=7-158x=-8x=-1------------19y-171=3y+2119y-3y=21+17116y=192y=192:16y=12-----------4x-36=3x-244x-3x=-24+36x=12----------6x-27=5x-206x-5x=-20+27x=7------------21-14x=15-15x-14x+15x=15-21x=-6
1) 3х-1=2(х-2) 3х-1=2х-4 3х-2х=-4+1 х=-3 2) 3(х+5)=х-3 3х+15=х-3 3х-х=-3+15 2х=12 х=6 3) 19(х+9)=3(х-8) 19х+171=3х-24 19х-3х=-24-171 16х=-195 х=-12