Jawabanmu

2014-03-27T14:07:35+07:00
P=(3x-2)
l= (x+3)
K = 42cm

K = 2(p+l)
42 = 2(3x-2+x+3)
21 = 4x+1
4x = 20
x = 5cm

maaf kalau salah:)
4 5 4
2014-03-27T14:14:54+07:00
Misal = k = 2×(p+l) 42= 2×(x+3)+2×(3x-2) 42 = 2x+6+6x-4 42 = 8x+2 42-2 = 8x+2-2 40 = 8x 40:8 = x 5 = x
3 2 3