tolong bantuin ngerjain kak nomer 23,pake caranya besok dikumpulin))): tolong bantuinn

Karton :
panjang = 30 & lebar = 40

Foto :
Panjang = 30 - 3 - 3 = 24 & lebar = 40 - x - x = 40 - 2x

Perbandingan panjang = perbandingan lebar
30/24 = 40/(40 - 2x)
3/24 = 4/(40 - 2x)
1/8 = 4/(40 - 2x)
40 - 2x = 8(4)
-2x = 32 - 40
-2x = -8
x = 4