Question 620554
  <pre><font face = "Tohoma" size = 3 color = "indigo"><b> 
Hi,
If you meant:
 y = 4x   and
 x + y  = 5
 x + 4x = 5       |Substituting the 4x for y
   5x = 5
    x = 1    and y = 4   (y = 4x = 4·1)
ordered pair (1,4) is the Solution for this system  
{{{drawing(300,300,   -6, 6, -6, 6,   grid(1),
circle(1, 4,0.3),
graph( 300, 300, -6, 6, -6, 6,0,4x, -x+5))}}}