Question

if x^2+y^2=56 and x-y=4,what is the average of x and y?

Answer 1

plz me solution

Answer 2

(x-y)^2=4^2
(x-y)^2=16
x^2-2xy+y^2=16
-2xy+x^2+y^2=16
-2xy+56=16
-2xy=16-56
-2xy=-40
xy=20
y=20/x
does this help iman?

Answer 3

so we have
y=20/x
then
x-y=4
can be rewritten as
x-20/x=4
x^2-20=4x
x^2+4x-20=0
we can find x
then plug into y=20/x to find y
then we can find (x+y)/2

Answer 4

(x - y)^2 = x^2 + y^2 -2xy

16 = 56 -2xy
2xy = 40
xy =20

you want average x +y
---- right?
2

(x+y)^2 = x^2 + y^2 +2xy
(x + y)^2 =96

x + y = sqrt(24)
-----
2

Answer 5

nice! :)