Question

sendo x = 4,777... e y = 2,666..., calcule o valor de

x + y

x -y

y - x

Answer 1

Olá Serginho,

 

$x + y => 4,777 + 2,666 = 7,443$

$x - y => 4,777 - 2,666 = 2,111$

$y -x => 2,666 - 4,777 = -2.111$

Answer 2

Olá, Serginho.

 

$<var>x = 4,777...=4+\frac79\\\\ y = 2,666...=2+\frac69\\\\ x + y=4+\frac79+2+\frac69=6+\frac{13}9=\frac{54+13}9=\frac{67}9}=\frac{63+4}9=7+\frac49\\\\ \Rightarrow \boxed{x+y=7,444...}\\\\ x - y=4+\frac79-2-\frac69=2+\frac19=2+0,111...\\\\ \Rightarrow \boxed{x-y=2,111...}\\\\\\ y - x=2+\frac69-4-\frac79=-2-\frac19=-(2+\frac19)=-(2+0,111...) \\\\ \Rightarrow \boxed{y-x=-2,111..}</var>$