Question:
Evaluate:
(i) 69 × 71
(ii) 94 × 106
Solution:
(i) $69 \times 71=(70-1) \times(70+1)=\left(70^{2}-1^{2}\right)=4900-1=4899$
(ii) $94 \times 106=(100-6) \times(100+6)=\left(100^{2}-6^{2}\right)=10000-36=9964$