Question

simplificar considerando sólo cambios de signo 7-y/y-7​

Answer 1

Simplificar fracción algebraica

                      $\displaystyle\ \frac{7-y}{y-7} = \frac{-(-7+y)}{y-7} =\frac{-(y-7)}{y-7} = -\frac{y-7}{y-7} = -1$