(i) +

= –

=

=

(ii) Let x be a rational number. Then,

+ x = -1

= -14

= 9 – 14

=

(iii) + x = 3

+ = 3

= 27

x =

(iv) x + = 4

23x + 15 = 92

23x = 92 – 15

23x = 77

x =