x+y=9
xy=4
x+y=9
subtrac x
y=9-x
subsitute
x(9-x)=4
9x-x^2=4
add to both sides
0=x^2-9x+4
use quadratice formula
if 0=ax^2+bx+c then
x=[tex] \frac{-b+/- \sqrt{b^{2}-4ac} }{2a} [/tex]
x^2-9x+4=0
a=1
b=-9
c=4
x=[tex] \frac{-(-9)+/- \sqrt{(-9)^{2}-4(1)4} }{2(1)} [/tex]
x=[tex] \frac{9+/- \sqrt{81-16} }{2} [/tex]
x=[tex] \frac{9+/- \sqrt{65} }{2} [/tex]
aprox
x=0.468817 or 8.5311
the numbers are interchangable so
the numbers are 0.468817 and 8.5311
