Question

O valor da expressão
$( \frac{1}{2}) + ( \frac{3}{4} ) - ( \frac{2}{5} )$
é:

a)
$\frac{1}{2}$
b)
$\frac{6}{11}$
c)
$\frac{33}{20}$
d)
$\frac{27}{30}$
e)
$\frac{17}{20}$
​

Answer 1

Resposta:

e)

$\frac{17}{20}$

Explicação:

(1/2)+(3/4)-(2/5) =

[(20÷2×1)+(20÷4×3)-(20÷5×2)]/20 =

[(10×1)+(5×3)-(4×2)]/20 =

[10+15-8]/20 =

[25-8]/20 =

17/20