Question

Calcule

a) 0,75 (1/5+2/8

Answer 1

a) 0,75 [1/5+2/8 (:2)/(:2)]
= 75/100 (:25)/(:25) . (1/5 + 1/4)
= 3/4 . (1/5 + 1/4)
= 3/4 . 1/5 + 3/4.1/4
= 3/20 + 3/16
= (4.3 + 5.3)/80
= (12+15)/80
= 27/80

Mmc (20,16)= 80
20,16: 2
10,8: 2
5, 4: 2
5,2: 2
5,1: 5
1,1
= 2.2.2.2.5
= 4.4.5
= 4.20
= 80

R.: 27/80

Answer 2

0,75 (1/5+2/8)
0,75.(0,2+1/4)
0,75.(0,2+0,25)
0,75.0,45
= 75/100 (:25)/(:25). 45/100
= 3/4 . 45/100 (:5)/(:5)
= 3/4 . 9/20
= 27/80