Question

What adds to get 9 and multplies to get 4

Answer 1

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=
`\frac{-b+/- \sqrt{b^(2)-4ac} }{2a}`

x^2-9x+4=0
a=1
b=-9
c=4

x=
`\frac{-(-9)+/- \sqrt{(-9)^(2)-4(1)4} }{2(1)}`
x=
`(9+/- √(81-16) )/(2)`
x=
`(9+/- √(65) )/(2)`
aprox
x=0.468817 or 8.5311

the numbers are interchangable so

the numbers are 0.468817 and 8.5311