Factorise: xcube-3xcube-9x-5.
NAditya1:
please somebody help me.
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Heya!!!!! here is your answer....
p(x) = x3 - 3x2 - 9x - 5
Factors of 5 = 1,5,-1,-5
p(1) = 13 - 3 x (1)2 - 9 x (1) - 5
= 1 -3 - 9 - 5
= 1 - 17 = - 16 ≠ 0
p(-1) = (-1)3 x 3 x (-1)2 - 9 x (-1) -5
= -1 - 3 + 9 - 5 = -9 + 9 = 0
p(-1) =0
∴ (x+1) is a factor of p(x)
p(x) ÷ (x+1)
x3 - 3x2 - 9x - 5 ÷ x + 1
= x2 - 4x - 5
x2 - 4x - 5
x2 - 5x + 1x - 5
= x ( x - 5) + 1 ( x - 5)
= ( x - 5) ( x + 1)
I HOPE THIS WILL HELP YOU OUT........
HAVE A GREAT DAY DEAR....
p(x) = x3 - 3x2 - 9x - 5
Factors of 5 = 1,5,-1,-5
p(1) = 13 - 3 x (1)2 - 9 x (1) - 5
= 1 -3 - 9 - 5
= 1 - 17 = - 16 ≠ 0
p(-1) = (-1)3 x 3 x (-1)2 - 9 x (-1) -5
= -1 - 3 + 9 - 5 = -9 + 9 = 0
p(-1) =0
∴ (x+1) is a factor of p(x)
p(x) ÷ (x+1)
x3 - 3x2 - 9x - 5 ÷ x + 1
= x2 - 4x - 5
x2 - 4x - 5
x2 - 5x + 1x - 5
= x ( x - 5) + 1 ( x - 5)
= ( x - 5) ( x + 1)
I HOPE THIS WILL HELP YOU OUT........
HAVE A GREAT DAY DEAR....
hi
ThankQ
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