1. (3/4+1/20)×1/2=2/5
1) 3/4+1/20= 15+1 = 16/20=4/5
20
2) 4/5×1/2=4×1 = 2/5
5×2
2.(7/12-1/3)×16/19=4/19
1) 7/12-1/3=7-4 = 3/12=1/4
12
2) 1/4×16/19=1×16 = 4/19
4×19
3. (7 3/5-2 4/15)×9/32=1 1/2
1) 7 3/5-2 4/15=38/5-34/15=114-34 = 80/15= 16/3
15
2) 16/3×9/32=16×9 = 3/2= 1 1/2
3×32
4. (11/24+1/6)×1 3/5= 1
1) 11/24+1/6=11+4 = 15/24=5/8
24
2) 5/8×1 3/5= 5/8×8/5= 1
