Explicação passo-a-passo:
a)
1/4 × 5/2 = 5/8
b)
7/ 3 x 3/5 = 21/15 = 7/5
c)
1/2 × 2/10 = 2/20 = 1/10
d)
7/12 × 3/5 = 21/60 = 7/20
e,)
9/10 × 4,/15 = 36/150 = 9/25
f)
12/15 × 6/9 = 72/135 = 24/45 = 8/15
