Question

Sendo (x+2, y - 3)= (2x+1, 3y - 1), determine o valor dex+y.
a) 0.
b) 1.
(X
c) 2.
d) -1.
e) -2.

Answer 1

Resposta:

Igualdade entre pares ordenados:

$\sf(x_1,y_1)=(x_2,x_2)\iff x_1=x_2~e~y_1=y_2$

Dado que:

$\sf(x+2,y-3)=(2x+1,3y-1)$

Temos:

$\sf x+2=2x+1~(i)$

$\sf 2x-x=2-1$

$\red{\sf x=1}$

$\sf y-3=3y-1~(ii)$

$\sf 3y-y=1-3$

$\sf 2y=-\,2$

$\red{\sf y=-\,1}$

Assim:

$\red{\sf x+y=1-1=0}$

Letra A