Answer:
is y=x^2 a proportional relationship?
[tex]{ \sf{yes. \: constant \: of \: proportionality = 1}}[/tex]
is y=2+x a proportional relationship?
[tex]{ \sf{no. \: unless \: y \: is \: proportinal \: to \: (2 + x)}}[/tex]
is y=2/x a proportional relationship?
[tex]{ \sf{yes. \: where \: proportianality \: constant \: is \: 2}}[/tex]
is y=2x a proportional relationship?
[tex]{ \sf{yeah. \: constant \: is \: 2}}[/tex]
