Given the polynomial:

x2y+2xy25x2y+xy2xy+y14y7xy2y+x+7\displaystyle -{x}^{{2}}{y}+{2}{x}{y}^{{2}}-{5}{x}^{{2}}{y}+{x}{y}^{{2}}-{x}{y}+{y}-{1}-{4}{y}-{7}{x}{y}-{2}{y}+{x}+{7}

Combine like terms