you multiply 4 to -6x and -3
you combined the one that has the same variable and no variable number like
(-72x )+ (-24x) = -96x
(-12) + 24 = 12
subtract 12 on both sides, like this -96 + 12-12 = 132-12 then you've got -96x = 120
you divide -96, like this -96x/-96 = 120/-96 , so you will got the x = -1.25