Question

If 2 and -4 are zeroes of the polynomial f(x) = x² + ax -8 the value of a


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Answer 1

Answer:

-2

Step-by-step explanation:

if b and c are the roots of the equation

then the equation can be written as

x²+(b+c)x+bc

similarly here

2 and -4 are zeroes of the polynomial f(x) = x² + ax -8 the value of a

therefore,

we can f(x) as x² +( 2+(-4))x+ 2(-4)

= x²+(-2)x-8

=x²-2x -8

comparing it with f(x) given

a= -2

Answer 2

Answer:

if we put 2 in x the answer is that the value of a is 2 .

or

if we put -4 in x the answer is that the value of a is -2

Step-by-step explanation:

if we put 2 in f(x) = x+ax -8

2²+2a-8=0

4+2a -8=0

-4+2a =0

2a = 4

a= 4/2

a = 2

if we put -4 in f(x) = x+ax -8

-4² -4a-8=0

16-8-4a = 0

8-4a=0

-4a=-8

a =-8 /4

a = -2