Hitunglah x dan y !!!

Mapel : Matematika
Kelas : IX SMP
Bab : Kesebangunan

Pembahasan :
CE/BC = DE/AB
6/(6 + 4) = x/30
6/10 = x/30
3/5 = x/30
5x = 90
x = 18

CE/BC = CD/AC
6/(6 + 4) = 21/(21 + y)
6/10 = 21/(21 + y)
3/5 = 21/(21 + y)
3(21 + y) = 105
63 + 3y = 105
3y = 42
y = 14