Jawabanmu

2014-06-05T09:11:15+07:00
68= 2(2x-5+x+3)
68 =2(3x-2)
68 =6x-4
68+4=6x
72 =6x
x=72:6 =12

2014-06-05T14:49:54+07:00
K=2(p+l)
68=2((2x-5)+(x+3))
68=2(3x-2)
68=6x-4
68+4=6x
72=6x
12cm.=c