Jawabanmu

2014-02-11T19:59:21+07:00
-2b= 6 - 4
4=6 + 2b
6=4 - 2b
b=(6-4):-2
-2=(6-4):b

2014-02-11T20:06:17+07:00
4 - 2b - 6 = 0
4 = 6 + 2b
-2b = 6 - 4
4 - 6 = 2b
b =  \frac{(6 - 4)}{2}