0.3(12x-16) = 0.4(12-3x)
0.3 is easier written as 3/10 and 0.4 easier written as 2/5, but in this case, 4/10 would help with the other fractions
3*12x/10-16*3/10 = 12*4/10 - 3x*4/10
36x/10-48/10 = 48/10 - 12x/10
since all the fractions are divided by 10, you can remove them totally by multiplying everything with 10
36x-48 = 48 - 12x
36x + 12x = 48 + 48
Here we moved the numbers, by adding them to both sides
48x = 48*2
we can find x by dividing by 48
x = 48*2/48
since we have a 48 both over and under the fraction we can cross out both
x = 2/1 = 2