Answer of question 5 (i) ,(ii), (iii), (iv)

5. Simplify:
(i) 179 × 179 – 21 × 21
(ii) 1.62 × 1.62 – 0.38 × 0.38
(iii) $\frac{297\times 297-203\times 203}{94}$
(iv) $\frac{23.71\times 23.71-16.29\times 16.29}{0.742}$