Complete question 3 (a, b) by using S4 Math quadratic equation.

S.4 Mathematics (Compulsory Part) Chapter 1 Quadratic Equations in One Unknown (Homew Ex 1E (3,5,8,9,14, 15, 16) 3. Mr. Lee is now x years old. His current age is the square of his age twenty years old. (a) Express the age of Mr Lee twenty years ago in terms of x. (b) Hence, find the current age of Mr Lee