Question

13. Find the values of a and b if x - 1 is factor of 2ax^2 + 6x + b and x + 1 is a factor of ax^2. + bx + 9.

a = 5, b = -4

a = -3, b = 4

a = -5, b = 4

a = -3, b = -4


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Answer 1

Step-by-step explanation:

since x-1 is a factor of

2ax²+6x+b then put x= 1

2a+6+b=0

2a+b= -6.................(1)

again

x+1 is the factor of ax²+bx+9 then put x= -1

a-b+9=0

a-b= -9.................(2)

(1)+(2)

3a= -15 =>. a= -5

putting a= -5 in (1)

2×(-5)+b= -6

b= -6+10=4

therefore, a= -5 , b= 4