Ex. 1. 1ff is a field and a, b,c ef; then prove that: (a) -(a +b) = (-a) +(-b) (b) a(b-c) = ab - ac

Ex. 1. 1fF is a field and a, b,c eF; then prove that: (7f F v &7TT a,b, c e F; m fE TU): (a) -(a +b) = (-a) +(-b) (b) a(b-c) = ab - ac