Question

Necesito resolver 3 ejercicios de metodo de sustitucion...
1. x- 5y = 8
_. -7x + 8y

2. 5m- 2n = 13
_. m + 3n = 6

3. 2w + 5z = -24
_. 8w - 3z = 19

Answer 1

Respuesta:

$m = 6 - 3n \\ 5(6 - 3n) - 2n = 13 \\ 30 - 15n - 2n = 13 \\ 17 = 17n \\ \frac{17}{17} = n \\ 1 = n$

m + 3(1) = 6

m = 6 - 3

m = 3

$w = \frac{ -24 - 5z}{2} \\ 8( \frac{ - 24 - 5z}{2}) - 3z = 19 \\ 4( - 24 - 5z) - 3z = 19 \\ - 96 - 20z - 3z = 19 \\ - 115 = 23z \\ \frac{ - 115}{23} = z \\ - 5 = z$

2w + 5(-5) = - 24

2w = - 24 + 25

w = 1/2