
Example: If one root of x^{2}  (a+1)x  21 = 0 is 3, find the value of a. Solution: If the roots of ax^{2} + bx + c = 0 are a and b then,
one root is 3, i.e. a = 3 Sum of the roots (a + b) = a + 1 3 + b = a + 1 Product of the roots (ab) = 21 Given that a = 3, Therefore, 3b = 21 b = 21/3 b = 7 3 + 7 = a + 1 a = 4  1 a = 3 Directions: Solve the following problems. Also write at least 5 examples of your own. 