Q.8 Verify a – (– b) = a + b for the following values of a and b.
(i) a = 21, b = 18
(ii) a = 118, b = 125
(iii) a = 75, b = 84
(iv) a= 28, 6 = 11

In question
a- (-b) = a+b
(i) If a=21 , b= 18
Then L.H.S = a-(-b) = 21-(-18) = 21+18 = 39
R.H.S = a+b= 21+18 = 39
L.H.S= R.H.S proved
(ii) If a=118 , b= 125
Then L.H.S = a-(-b) = 118-(-125) = 118+125 = 243
R.H.S = a+b= 118+125 = 243
L.H.S= R.H.S proved
(iii) If a=75 , b= 84
Then L.H.S = a-(-b) = 75-(-84) = 75+84 = 159
R.H.S = a+b= 75+85 = 159
L.H.S= R.H.S proved
(iv) If a=28 , b= 11
Then L.H.S = a-(-b) = 28-(-11) = 28+11= 39
R.H.S = a+b= 28+11 = 39
L.H.S= R.H.S proved