Tìm số nguyên x, biết a) (-12).x = (-15).(-4) -12 b) (-9).x +3 = (-2).(-7) +16 c) (-12).x -34 = 2

a)

−12.x=−15.−4−12−12.x=60−12−12.x=48              x=48:−12              x=−4

b) 

−9.x+3=−2.−7+16−9.x+3=14+16−9.x+3=30−9.x         =30−3−9.x         =27            x         =27:−9            x         =−3

c)

−12.x−34=2−12.x             =2+34−12.x             =36              x              =36:−12              x              =−3