if x+y= -4 and xy=2, then find the value of x²+y²
Answers
Answered by
88
x+y=-4
x=-4-y (call this equation 1)
also xy=2
y=2/x (call this equation 2)
since x =-4-y thus usimg this value of x in equation 2 , we get
y=2/-4-y
-4y-y^2=2 ( cross multiplication)
-y^2-4y=2
or y^2+4y=-2
y^2+4y+2=O
after solving this quad. equation get value of y n then using this value of y get value of x usimg equation 1 then put on this value of x n y in given problem n get the answer ; )
x=-4-y (call this equation 1)
also xy=2
y=2/x (call this equation 2)
since x =-4-y thus usimg this value of x in equation 2 , we get
y=2/-4-y
-4y-y^2=2 ( cross multiplication)
-y^2-4y=2
or y^2+4y=-2
y^2+4y+2=O
after solving this quad. equation get value of y n then using this value of y get value of x usimg equation 1 then put on this value of x n y in given problem n get the answer ; )
Jashanpreet:
please complete it
ok
but can u plz send me the answer of this qs first
i have no answer
ok wait i will send
thanks
solve the quad equation using discremenant method n after doing so we get two answers of y 1) -2 -underroot 2 or -2+underroot 2 then usimg these two values of y find two values of x using equation 1 and use values of x n y in problem ...this qs will have 2 solutions as we get two solutions for x n y
thank you very much
ur welcome
Answered by
73
(x+y)^-2xy
(-4)^-2×2
16-4
12.
(-4)^-2×2
16-4
12.
Similar questions