Factorise (x + 4)3 – 9x – 36
Answers
Answered by
1
Answer:
3x+12-9x-36
3x-9x+12-36
-6x+-24
Answered by
2
Answer:
hope it helps you plz ☺️☺️ me
Step-by-step explanation:
We have,
(x+4)
3
−9x−36
=x
3
+64+12x
2
+48x−9x−36[∵(a+b)
3
=a
3
+b
3
+3a
2
b+3ab
2
]
=x
3
+12x
2
+39x+28
By hit and trial x+1 is one of the factor.
So, Divide x
3
+12x
2
+39x+28 by x+1, we get
x
3
+12x
2
+39x+28=(x+1)(x
2
+11x+28)
⇒x
3
+12x
2
+39x+28=(x+1)(x
2
+7x+4x+28)
⇒x
3
+12x
2
+39x+28=(x+1)[x(x+7)+4(x+7)]
⇒x
3
+12x
2
+39x+28=(x+1)(x+4)(x+7)
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