Q9 of 90 Page 115

ab - a - b + 1 = ?

ab - a - b + 1

By using Splitting the middle term

= ab - a - b + 1

= (1 - a) - b(1 - a)

= (1 - a)(1 - b)

Solve:

5 years ago a man was 7 times as old as his son. After 5 years he will be thrice as old as his son. Find their present ages.

3 + 23x - 8x² = ?

7x² - 19x - 6 = ?