Question

ME AJUDEM PFR---------------------

Answer 1

Explicação passo a passo:

Método da adição

$a) \left \{ {{2x + y =5} \atop {3x - y = 10}} \right.\\5x = 15 \\x = 3\\2.3 + y = 5\\6 + y = 5\\y = -1\\\\b) \left \{ {{5x - y = 7} \atop {2x + y = 7}} \right.\\7x = 14\\x = 2\\5.2 - y = 7\\10 - y = 7\\y = 3\\\\c) \left \{ {{4x-y = -4}.(-1) \atop {5x - y = 1}} \right.\\\left \{ {{-4x+y=4} \atop {5x-y=1}} \right.\\\\-x = 5\\x = 5\\\ 5.5- y = 1\\y = 24$

$d) \left \{ {{x+2y = 6} \atop {x-y = 2.(-1)}} \right. \\\left \{ {{x + 2y = 6} \atop {-x+y = -2}} \right.\\3y = 4\\y = \frac{4}{3}\\x+2.\frac{4}{3} = 6\\x = 6 - \frac{8}{3}\\x = \frac{10}{3}$