Pake caranya ya nomer 19,20,21

19.
m1=m2 ( sejajar)
y/x = 2/3
y-y1 = m(x-x1)
y-0   = 2/3 (x+6)
3y    = 2x+12
3y-2x-12 = 0 (tdk ada jawaban di option)

20.
p = 3l
1/2 kll = 24 m
p+l     = 24 m
3l+l    = 24 m
4l       = 24 m
l         = 6 m
p        = 3(6m) =18 m
laus    = pxl
          = 18 mx 6m
          = 108 m^2

21. b. a < b+c