4x-9(x-7)=-12                                              15x(-3-(19-18x))+3x=x+90+2x

15х(-3(19-18))+3х=х+90+2х15х(-57+54х)+3х=х+90+2х-855х+660х^+3х=х+90+2х660х^-855х+3х-х-2х=90660х^-855х=9015х(44х-57)=901)15х=90 2)44х-57=90 х=6 44х=90-57 44х=33 х=3/4