Question

qual a resposta do item "e)" ???

Answer 1

(I)
$4x + 2y = - 7 \\ \\ y = \frac{- 7 +-4x}{2}$

(II)
$2x + 3y = - \frac{1}{2}$

Substituindo (I) em (II):

$2x + 3( \frac{-7 - 4x}{2}) = - \frac{1}{2} \\ \\ 2x + \frac{-21 - 12x}{2} = - \frac{1}{2} \\ \\ \frac{4x}{2} + \frac{-21-12x}{2} = - \frac{1}{2} \\ \\ -8x - 21 = - \frac{1}{2} .2 \\ \\ -8x - 21 = -1 \\ \\ 8x = -20 \\ \\ x = - \frac{5}{2}$


$y = \frac{-7 - 4x}{2} \\ \\ y = \frac{-7-4.(- \frac{5}{2}) }{2} \\ \\ y = \frac{-7 + 10}{2} \\ \\ y = \frac{3}{2}$

Portanto:

$x = - \frac{5}{2} \\ \\ y = \frac{3}{2}$