Answers

2014-06-25T13:14:31+08:00
X= 67, because 190- 210= -20 then 19-21= -3 then add -3+-20= +23 
100-23= 77
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2014-06-25T13:48:29+08:00
X=78, because |190-210|= -20, then |19-21|= -2 , then  the equation will became |-20| + |-2| + x = 100 , if you removed the bar the negative sign will became positive , then the equation will became 20 + 2 + x = 100,add 20 and 2,  22 + x = 100, and transpose 22 to the right side of the equation and it became negative, then the equation will be, x=100-22 and x=78...
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