(x+y)² -z²=4, (y+z)²-x²=9, (z+x)²-y²=36 then (x+y+z)=?
Answers
Answered by
5
step 1
open squares of all equations
step 2
add all equations
u will have
x^2+y^2+z^2+2xy+2yz+2zx=49
as
(x+y+z)^2=x^2+y^2+z^2+2xy+2yz+2zx
now
in present case
(x+y+z)^2=49
taking square root
x+y+z=+7 or x+y+z= -7
open squares of all equations
step 2
add all equations
u will have
x^2+y^2+z^2+2xy+2yz+2zx=49
as
(x+y+z)^2=x^2+y^2+z^2+2xy+2yz+2zx
now
in present case
(x+y+z)^2=49
taking square root
x+y+z=+7 or x+y+z= -7
140536:
thanks
Answered by
2
please see the attachment.the answer is plus minus 7
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