Answer:
1)12 2)20 3) i cant see it 4) i cant see it
Step-by-step explanation:
1)12 why- change 3 into 3/1 change 1/4 into 4/1
3/1x4/1= 12/1= 12
2)20 why- change 4 into 4/1, change 1/5 into 5/1
4/1x5/1=20
3)I cant see it same with 4)
