Question

me ajudem e pra hoje agora

Answer 1

$\left \{ {{2a-b=1*(-2)} \atop {7a-2b=3 *(-2)}} \right. = \left \{ {{-4a+2b = -2} \atop {7a-2b=3}} \right. = 3a = 1 a = \frac{1}{3}$ $a = \frac{1}{3} =\ \textgreater \ substituindo =\ \textgreater \ 2x *\frac{1}{3} -b = 1 ==\ \textgreater \ b = - \frac{1}{3}$
$a = \frac{1}{3}$
espero ter ajudado