Question

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, b = 11

Answer 1

(i) a = 21, b = 18

a − (−b) = 21 − (−18) = 21 + 18 = 39

a + b = 21 + 18 = 39

∴a − (−b) = a + b = 39

(ii) a = 118, b = 125

a − (−b) = 118 − (−125) = 118 + 125 = 243

a + b = 118 + 125 = 243

∴a − (−b) = a + b = 243

(iii) a = 75, b = 84

a − (−b) = 75 − (−84) = 75 + 84 = 159

a + b = 75 + 84 = 159

∴ a − (−b) = a + b = 159

(iv) a = 28, b = 11

a − (−b) = 28 − (−11) = 28 + 11 = 39

a + b = 28 + 11 = 39

∴ a − (−b) = a + b = 39