Question

alguem por favor pode resolver esta equação x- y =6  x+y = -7

Answer 1

{x - y = 6 ⇒ x = 6+y
{x+y= -7
6 + y + y = -7
6+ 2y = -7
 2y = -13 ⇒ y = -13/2

x = 6+y⇒ x= 6+(-13/2)⇒x= 6-13/2⇒ x= -1/2

Answer 2

$[tex]x - y = 6\\\\ x - y - 6 = 0 \\\\ x + y = -7 \\\\ x + y + 7 = 0 \\\\ Some ...\\\\ (x - y - 6 )+ (x+ y + 7) = 0 \\\\ 2x = -13\\\\ \boxed{x = -\frac{13}{2} }\\\\ x + y = -7 \toy = -7 -x\\\\ y = -7 - \frac{13}{2}\\\\ \boxed{y = -\frac{1}{2} }$ [/tex]