Março 23, 2020

por Britta

Qual é a soma de $\frac{2}{5}$ $2 / 5$ e $\frac{2}{4}$ $2 / 4$ ?

Responda:

$\frac{9}{10}$ $9/10$

Explicação:

First note that $\frac{2}{4} may be simplified$ $2/4" may be simplified"$

$cancel(2)^1/cancel(4)^2=1/2$

hence $2/5+1/2" is now the sum"$

Since the denominators ( 5 and 2 ) are different we cannot add them. We have to have a common denominator before we can do this.
The lowest common denominator for 2 and 5 is 10. We now express both fractions with a denominator of 10.

$(2/5xx2/2)+(1/2xx5/5)=4/10+5/10$

Now that the denominators are the same we just add the numerators, leaving the denominator(do not add)

$rArr2/5+1/2=4/10+5/10=9/10$