Question

If the equation formed by decreasing each root of

ax² + bx + c = 0 by 1 is 2x² + 8x + 2 = 0 then

• A. a = –b
• B. b = –c
• C. c = –a
• D. b = a + c

Answer 1

Answer: (B)

b = –c

Answer 2

Let roots of

ax² + bx + c = 0 are a & b then roots of equation

2x² + 8x + 2 = 0 are a – 1, b – 1

a – 1 + b – 1 = –8/2 = – 4

a + b = – 2 (a – 1)(b – 1) = 2/2 = 1

–b/a = – 2 ab – (a + b) + 1 = 1

b = 2a ab = + (a + b)

b + c = 0