Q463
If x + y = 14 and x3 + y3 = 1064, then the value of (x - y)2 is:
A.
100
B.
36
AnswerC.
81
D.
64
Answer: Option B
Solution
Answer: Option B
Solution:
x3 + y3 = (x + y)[(x + y)2 - 3xy]1064 = 14[142 - 3xy]
76 = 196 - 3xy
3xy = 120
xy = 40
(x - y)2
= (x + y)2 - 4xy
= 142 - 4 × 40
= 196 - 160
= 36