Tolong Jawab nomer 3 dan 4...sama caranya ... makasihhhhhhhhhhhh

nomor 4nya gak ada dek, no. 2 dan 4 aja ya.
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2) 18 banding 12
°°. 12 banding 8
°°. x banding 6
. 12/x = 8/6 kali silang 12.6 = 8.x
. 72 = 8x. x= 72/8. x= 9

3) AB banding DE. 20 banding 15
°°. CD banding CA. 24+x banding 24
°°. 20/15 = (24+x)/24 kali silang
°°. 20.24 = 15.(24+x)
°°. 480 = 360+15x // 15x=480-360//15x=120// x=8