the difference of two numbers is 21 and their product is 4
Answers
Answered by
3
Answer:
please explain your question better...
Answered by
2
Answer:
ANSWER
Let the number be x and y.
x−y=4,xy=21
x
3
−y
3
=(x−y)[x
2
+y
2
+xy−2xy+2xy]
=(x−y)[(x−y)
2
+3xy]
=4(16+63)=4×79=316
x−y=4⇒ squaring on both sides x
2
−y
2
−2xy=16
⇒(x+y)
2
−2xy−2xy=16
Step-by-step explanation:
ANSWER
Let the number be x and y.
x−y=4,xy=21
x
3
−y
3
=(x−y)[x
2
+y
2
+xy−2xy+2xy]
=(x−y)[(x−y)
2
+3xy]
=4(16+63)=4×79=316
x−y=4⇒ squaring on both sides x
2
−y
2
−2xy=16
⇒(x+y)
2
−2xy−2xy=16
⇒(x+y)
2
=16+4×21
x+y=10
∴x
3
+y
3
=(x+y)[x
2
+y
2
−xy]
=(x+y)(x
2
+y
2
−xy+2xy−2xy)
(10)[(x+y)
2
−3xy]⇒10(100−63)=370
Required ratio =
x
3
−y
3
x
3
+y
3
=370:316=185:158
Hence, option 'C' is correct.
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