Posted by Cassidy on Sunday, August 25, 2013 at 7:27pm.
5x10 = 2(x+4)

8th Math  Ms. Sue, Sunday, August 25, 2013 at 7:33pm
5x  10 = 2  (x + 4)
4x = 12  4
4x = 8
x = 2 
8th Math  Cassidy, Sunday, August 25, 2013 at 7:37pm
Thx Ms.Sue! But why the +4 became 4? I confused with this part

8th Math  Ms. Sue, Sunday, August 25, 2013 at 7:40pm
There's a minus sign in front of the quantity in parentheses
2  (x + 4)
A + and a  is always a minus. 
8th Math  Cassidy, Sunday, August 25, 2013 at 7:58pm
what if there's a sign of positive in front of the quantity in parenthese, such like 2+(x+4)....which mean the +4 will be staying the same as +4?

8th Math  Ms. Sue, Sunday, August 25, 2013 at 7:59pm
Yes.