Выполните действия c/c+2-c^2-2c-4/c^2+2c
[ с/(с+2) ] - [ (c^2 -2c - 4) / (c^2 + 2c) ] = = [ c/(c+2) ] - [ (c^2 - 2c - 4) / ( c(c+2)) ] = = (c *c - (c^2 -2c - 4) ) / ( c(c+2) ) = = (c^2 - c^2 +2c + 4) / (c(c+2)) = = (2c+4)/ (c(c+2)) = = ( 2*(c+2) ) / ( c(c+2) ) = = 2/c