If 2 and 6 are the roots of the equation ax2+bx+1=0, then the quadratic equation, whose roots are 12a+b and 16a+b, is :
- x2+8x+12=0
- 2x2+11x+12=0
- 4x2+14x+12=0
- x2+10x+16=0
Answer
(1) x2+8x+12=0
Solution
Sum of roots: - ba=2+6=8; product: 1a=2 6=12
a= 112, b=-8a=- 23
2a+b= 16- 23=- 12 first root =-2
6a+b= 12- 23=- 16 second root =-6
Sum =-8, product =12 x2+8x+12=0
Answer: (1)