Respuesta:
5) x = 3 y = 5
1) -6
2) 19/13
Explicación paso a paso:
Método de igualación:
5) x+2y = 13 => x = 13 - 2y
x+ 3y = 18 => x = 18 - 3y
13 - 2y = 18 - 3y
y = 5 x = 3
1) 5x - 3y = 21 => x = 21 +3y/5
x + 2y =-1 => x = -1 - 2y
21 +3y/5 = -1 - 2y
21+3y = -5 - 10y
13y = -26 => y = -2 x = 3
Luego calcula "xy"
xy = 3(-2) = -6
2) 3x + 5y = 1 => x = 1 - 5y/3
2x - y = 8 => x = 8 + y/2
1 - 5y/3 = 8 + y/2
2 - 10y = 24 + 3y
-13y = 22 => y = -22/13 x = 41/13
Luego indicar "x + y"
x + y = 41/13 + (-22/13) = 19/13
RPTA:
5) x = 3 y = 5
1) -6
2) 19/13
