If a and b are the roots of the equation x2 - 9x + 20 = 0, find the value of a2 + b2 + ab?
Answers.
A) 57	B) 59	C) 61	D) 63	E) 65

Rationale: "a 2 + b 2 + ab = a 2 + b 2 + 2 ab - ab i . e . , ( a + b ) 2 - ab from x 2 - 9 x + 20 = 0 , we have a + b = 9 and ab = 20 . hence the value of required expression ( 9 ) 2 - 20 = 61 . option c"
Answer: C