Question

calcule mentalmente o valor de cada uma das expressoes (a) 3/4 •1/4 (b) 1-1/6 (c) 4/7+2/5+4/7+3/5

Answer 1

a) 3/4 x 1/4 = 0,75 x 0,25 = 0,1875

b) 1-1/6 = 5/6 = 0,833 

c) 4/7 + 2/5 + 4/7 + 3/5 = (4/7+4/7 = 8/7  e 2/3+3/5 = 5/5=1, logo 8/7 + 1 = 9/7 = 1,285