Question

3. Rezolvaţi în mulţimea numerelor reale sistemul de ecuații
4x - y = 5
3x+y=9​

Answer 1

 

$\displaystyle\bf\\\\4x - y = 5\\3x+y=9\\\\\textbf{Adunam ecuatiile s8i se reduce y.}\\\\7x~~~/~~= 14~~~~~Semnul~~(/)~arata~ca~y~nu~mai~este.\\\\7x=14\\\\x=\frac{14}{7}\\\\\boxed{\bf~x=2}\\\\3x+y=9\\\\3\cdot2+y=9\\\\6+y=9\\\\y=9-6\\\\\boxed{\bf~y=3}$