Question

Calcule as expressão a)x/5 . 2 x x/10 - 1 =4 ajuda
B 1/2 + 1/4 + 1/2
C ) 7/8 +1/5+3/8+4/5
D)0,25+1/2+1/2-0,25?

Answer 1

A primeira está confusa. Parece incompleta.
Vamos lá:
a) x/5 . 2/x = x/5 . 10x/5 = 10x/5

x/10 - 1/10x = 4/1
x - 1/10 = 40/10 = 39

b) 1/2 + 1/4 + 1/2 = 2/4 + 1/4 + 2/4 = 5/4

c) 7/8 + 1/5 + 3/8 + 4/5 =
35/40 + 8/40 + 15/40 + 32/40 = 90/40

d) 25/100 + 1/2 + 1/2 -25/100
1/4 + 1/2 + 1/2 - 1/4

1/4 + 2/4 + 2/4 -1/4 = 4/4 = 1