Question

Which is the value of x if x-y=6 And x+y=8?

Answer 1

Answer:

The value of x is 7

hope it helps you...

Answer 2

Answer:

Given:

If x-y=6 and xy=8, what is the value of x²+y²?

Solution:

x - y = 6, ==> x = 6 + y

x y = 8, ==> (6+y)y = 8,==> 6y + y22 =8, ==> y22 + 6y = 8

y22 + 6y + 9 = 8 + 9, ==> y22 + 6y + 9 = 17

y22 + 6y + 9 = 17 , ==> (y + 3)22 = 17, ==> y + 3 = ±17−−√±17, ==>

y = ±17−−√±17 -3

xy = 8

x = 8y8y, ==> 8±17√−38±17−3, ==> 3±17−−√3±17

x22 + y22 = ?

(3−17−−√)2+(−3−17−−√)2=52(3−17)2+(−3−17)2=52

(3+17−−√)2+(−3+17−−√)2