Question

determine os pares ordenados X+2y=4 y2-xy=7

Answer 1

{2x -y=-3 
2(5-2y) -y =-3 
10-4y-y=-3 
-5y=-3-10 
-5y=-13 
y = 13/5 

x=5-2y = 5 -2(13/5)= 5 -26/5 = 25-26 /5 = -1/5