Question

ayudenme plis

1.- resuelve los siguientes sistemas de dos ecuaciones utiliza0ndo el metodo de suma y resta o tambien llamado de reducció. calcula el valor de las incognitas " x " y " y "


a) 2x + y = 8
x - 4y = -5

b) 2x - 6y = 4
3x + 2y = 17

c) x + y = 17
4x - y = 43

d) 2x + 3y = 5
3x - 4y = -1​

Answer 1

Respuesta:

a) x = 3; y = 2 b) x = 5; y = 1 c) x = 12; y = 5 d) x = 1; y = 1

Explicación paso a paso:

a) x = 3; y = 2

2x + y = 8 => 8x + 4y = 32}

x - 4y = -5 => x - 4y = -5 } => 9x = 27 => x = 27/9 = 3 =>

=> 2*3 + y = 8 => y = 8 - 6 = 2

b) x = 5; y = 1

2x - 6y = 4 => x - 3y = 2 => -3x + 9y = -6 }

3x + 2y = 17 => 3x + 2y = 17 => 3x + 2y = 17} =>

=> 11y = 11 => y = 11/11 = 1 =>

=> x - 3*1 = 2 => x = 2 + 3 = 5

c) x = 12; y = 5

x + y = 17 => -4x - 4y = -68}

4x - y = 43 => 4x - y = 43 } => 5y = 25 => y = 25/5 = 5 =>

=> x + 5 = 17 => x = 17 - 5 = 12

d) x = 1; y = 1

2x + 3y = 5 => 8x + 12y = 20}

3x - 4y = -1 => 9x - 12y = -3 } => 17x = 17 =>

=> x = 17/17 = 1 => 2*1 + 3y = 5 => 3y = 3 => y = 3/3 = 1