27a^3 - 1/216b^3 - 9/2a^2b + 1/4 ab^2 it's urgent please answer me fast....
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Answered by
1
Answer:
We know that
(a+b)
3
=a
3
+b
3
+3a
2
b+3ab
2
and (a−b)
3
=a
3
+b
3
−3a
2
b−3ab
2
(i) 8a
3
+b
3
+12a
2
b+6ab
2
=(2a)
3
+(b)
3
+3(2a)
2
(b)+3(2a)(b)
2
=(2a+b)
3
(ii) 8a
3
+b
3
−12a
2
b−6ab
2
=(2a)
3
+(b)
3
−3(2a)
2
(b)−3(2a)(b)
2
=(2a−b)
3
(iii) 27−125a
3
−135a+225a
2
=(3)
3
+(−5a)
3
−3(3)
2
(−5a)−3(3)(−5a)
2
=(3−5a)
3
(iv) 64a
3
−27b
3
−144a
2
b+108ab
2
=(4a)
3
+(−3b)
3
+3(4a)
2
(−3b)+3(4a)(−3b)
2
=(4a−3b)
3
(v) 27p
3
+
216
1
−
2
9
p
2
+
4
1
p
=(3p)
3
(−
6
1
)
3
+3(3p)(−
6
1
)
2
+3(3p)(−
6
1
)
2
=(3p−
6
1
)
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