(i) Divide 140 by 2 to get 70, divide 70 by 2 to get 35, divide 35 by 5 to get 7. So 140 = $2 \times 2$ × $5 \times 7$ = 2² × $5 \times 7$. (ii) Divide 156 by 2 to get 78, divide 78 by 2 to get 39, divide 39 by 3 to get 13. So 156 = $2 \times 2$ × $3 \times 13$ = 2² × $3 \times 13$. (iii) Divide 3825 by 3 to get 1275, divide 1275 by 3 to get 425, divide 425 by 5 to get 85, divide 85 by 5 to get 17. So 3825 = 3² × 5² × 17. (iv) Divide 5005 by 5 to get 1001, divide 1001 by 7 to get 143, divide 143 by 11 to get 13. So 5005 = $5 \times 7$ × $11 \times 13$. (v) Divide 7429 by 17 to get 437, divide 437 by 19 to get 23. So 7429 = $17 \times 19$ × 23.