Question

5) x+2y = 13
x+ 3y = 18

1) 5x - 3y = 21
x + 2y =-1
Luego calcula "xy"

2) 3x + 5y = 1
2x - y = 8
Luego indicar "x + y"​

Answer 1

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