Question

if x+2y=8 and xy=8 find the value of x

Answer 1

xy=8
y=8/x
X+2y =8
put value y in eq
X+2×8/X =8
x²+16 =8x
x²-8x+16=0
x²-4x-4x+16=0
X(x-4)+4(x-4)=0
(X+4)(x-4)=0
so, X+4=0
X =-4
and x-4=0
X=4

Answer 2

Xy=8

Y=8/x

X+2y=8

X+2*8/x=8

X+16/x=8

X^2-8x+16=0

X=4