I have 6 systems questions which i dont understand at all. help.how do you solve these?

1.x+y=4
y=2x+1



2.x+y=10
y=x+8



3.x=y-1
y=4-2x

• x+y=4
  y=2x+1
  substitute value of y in x
  x+2x+1=4
  3x+1=4
  3x=3
  x=1
  so y=2(x)+1
  y=3
  similarly
  for second
  x=1
  y=9
  and for third
  x=1
  and y=2
• 10 years agoHelpfull: Yes(0) No(0)