Question

if X= 1 is a common root of ax^2+ax+2=0 and x^2+x+b=0 then ab is equal to:
a)1
b)2
c)4
d)3

Answer 1

Answer:

In(1)

ax^2+ax+2=0

a×1^2+a*1+2=0

a+a+2=

2a=-2

a= -1

in (2)

x^2+x+b=0

1+1+b=0

2+b=0

b= -2

Therefore, ab=. -2*-1

2. Answer

ab=2

Hope it helps.................