If X – Y =3, and XY =10 , find X+Y.
Answers
Answered by
0
Answer:
Given that: x−y=3 And xy = 10
Using the given identity: (a−b)
2
= a
2
−2ab+b
2
So, (x−y)
2
= x
2
−2xy+y
2
⇒ (x−y)
2
= x
2
−2(10)+y
2
⇒ (3)
2
= x
2
−20+y
2
⇒ 9 = x
2
+y
2
−20
⇒ 9+20 =x
2
+y
2
⇒ x
2
+y
2
= 29
The correct answer is x
2
+y
2
=29
Answered by
0
Step-by-step explanation:
x-y=3
xy=10
y=10/x
x-10/x=3
x²-10=3x
x²-3x-10=0
x²-5x+2x-10=0
(x-5)(x+2)=0
x=5,-2
NOW
y=10/x
Y=10/5,-10/2
Y=2,-5
if we take only positive values of x and y then
X+Y=5+2=7
if we take only negative values of x and y then
x+y=-7
if we take positive value of x and negative value of y then
x+y=0
if we take positive value of y and negative value of x then
x+y=0
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