What's name the reciprocal of 7

The ratio pv to nrt is plotted against pressure for ch4 at 0°c and 200°c. why does the curve for 0°c drop below the horizontal line for an ideal gas whereas the curve for 200°c does not?

Express in the simplest form: (x^2+9x+14/x^2-49) / (3x+6/x^2+x-56)

Idon’t understand! use slope intercept form to solve: through: (2,5) slope= undefined