Answer:
20
Step-by-step explanation:
420-400=20
centi = a unit / 100
milli = a unit / 1000
centiX = 10 milliX
6m+5-3m=7(m-1)
3m+5=7m-1
5+1=7m-3m
6=4m
6/4=m
3/2=m
I think it is correct .
x + 1 = -x + (-5)
2x + 1 = -5
2x = -6
x = -3