Question 404687
  <pre><font size = 3 color = "indigo"><b>
Hi
y = 2x+1  
x+y = 3y-20   |good work!
x  + (2x+1) = 3(2x+1) - 20   |substituting for y
solving for x
 3x + 1 = 6x + 3 - 20
      18 = 3x
       x = 6  and y = 13  (2x+1)

CHECKING our Answer***
 y = 2x+1  
13 = 2*6 + 1