Question

If ax3+bx2-x+4 has x-2 as a factor and leaves a remainder 5 when divided by

X+2,find the value of a and b



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Answer 1

Answer:

here is the answer

x=-2(x+2)

a(-2)³+b(-2)²-(-2)+4

=-9a+4b+6.......(1)

x=2(x-2)

a(2)³+b(2)²-(2)+4

=9a+4b+2.....(2)

add both eq.

-9a+4b+6+9a+4b+2=0

=4b+6+4b+2

=8b+8

so,b=(-1)

now put the value of b in eq.

9a+4*-1+2=0

9a-4+2=0

9a-2

9a=2

a=2/9

a=0.2222

a=0.222,b=(-1)