X(X+1)=110 what is the value of x
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Answered by
1
Answer:
Step-by-step explanation:
(x+
x
1
)
3
=(x
3
+
x
3
1
)+3(x+
x
1
)
⇒ (x+
x
1
)
3
=110+3(x+
x
1
)
Let y=x+
x
1
⇒ y
3
=110+3y
⇒ y
3
−3y−110=0
⇒ y
3
−5y
2
+5y
2
−3y−110=0
⇒ y
2
(y−5)+5y
2
−25y+22y−110=0
⇒ y
2
(y−5)+5y(y−5)+22(y−5)=0
⇒ (y−5)(y
2
+5y+22)=0
⇒ y=5 or y=
2
−5±3
7
i
∴ x+
x
1
=5
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