If x + y = 27,
x2 + y2 = 425
Find (x - y)2
Answer & explanation
Correct answer: option 2
Formula: (x + y)2 = x2 + y2 + 2xy
⇒ (27)2 = 425 + 2xy
⇒ 729 - 425 = 2xy
⇒ 2xy = 304
Now,
⇒ (x - y)2 = x2 + y2 - 2xy
⇒ (x - y)2 = 425 - 304 = 121
If x + y = 27,
x2 + y2 = 425
Find (x - y)2
Correct answer: option 2
Formula: (x + y)2 = x2 + y2 + 2xy
⇒ (27)2 = 425 + 2xy
⇒ 729 - 425 = 2xy
⇒ 2xy = 304
Now,
⇒ (x - y)2 = x2 + y2 - 2xy
⇒ (x - y)2 = 425 - 304 = 121