assalamualaikum bantu jawabannya ukhty / akhy syukron ;)

2. A = 12 (12² = 12 x 12 = 144)
B = 16 (16² = 16 x 16 = 256)
C = 24 (24² = 24 x 24 = 576)
D = 30 (30² = 30 x 30 = 900)

3. maaf soalnya kurang jelas :)

maaf kalau salah :)