X . [ (5-x)/(x+1)] [ x+ (5-x) / (x+1) = 6

c) x . [ (5-x)/(x+1)] [ x+ (5-x) / (x+1) = 6
d) [ (7x-x^2) / (x+1) ] . [ (7+x^2) / (x+1) ] = 10
e) [ (3x-x^2) / (x-2) ] . [ (x^2-6)/(x-2)] = 2